PATENT DOCUMENT

Publication Number: US-7671804-B2
Application Number: US-51643306-A
Country: US
Kind Code: B2

Title: Tunable antennas for handheld devices

Abstract:
A compact tunable antenna for a handheld electronic device and methods for calibrating and using compact tunable antennas are provided. The antenna can have multiple ports. Each port can have an associated feed and ground. The antenna design can be implemented with a small footprint while covering a large bandwidth. The antenna can have a radiating element formed from a conductive structure such as a patch or helix. The antenna can be shaped to accommodate buttons and other components in the handheld device. The antenna may be connected to a printed circuit board in the handheld device using springs, pogo pins, and other suitable connecting structures. Radio-frequency switches and passive components such as duplexers and diplexers may be used to couple radio-frequency transceiver circuitry to the different feeds of the antenna. Antenna efficiency can be enhanced by avoiding the use of capacitive loading for antenna tuning.

Claims:
1. A tunable multipart handheld electronic device patch antenna, comprising:
 a ground terminal; 
 a substantially planar radiating element located above the ground terminal that is electrically connected to the ground terminal; and 
 at least first and second antenna feeds, wherein the first antenna feed is electrically connected to the radiating element at a first location, wherein the second antenna feed is electrically connected to the radiating element at a second location that is different from the first location, wherein the first antenna feed and the ground terminal form a first antenna port through which antenna signals are transmitted and received, and wherein the second antenna feed and the ground terminal form a second antenna port through which antenna signals are transmitted and received. 
 
   
   
     2. The tunable multiport handheld electronic device patch antenna defined in  claim 1  wherein the substantially planar radiating element and ground terminal form a planar-inverted-F antenna (PIFA) structure and wherein the first and second antenna feeds form feeds for the PIFA structure. 
   
   
     3. The tunable multiport handheld electronic device patch antenna defined in  claim 2  wherein the radiating element comprises a metal antenna structure without adjustable capacitive loading. 
   
   
     4. The tunable multiport handheld electronic device patch antenna defined in  claim 2  wherein the radiating element comprises first, second, and third integral elongated portions, wherein the first elongated portion forms the ground terminal, wherein the second elongated portion forms the first feed, and wherein the third elongated portion forms the second feed. 
   
   
     5. The tunable multiport handheld electronic device patch antenna defined in  claim 2  wherein the radiating element comprises metal and is configured to operate at a frequency range associated with a first cellular telephone band when the first antenna port is used and is configured to operate at a frequency range associated with a second cellular telephone band that is different from the first cellular telephone band when the second antenna port is used. 
   
   
     6. The tunable multiport handheld electronic device patch antenna defined in  claim 5  wherein selecting between the first port and second port occurs without the use of adjustable capacitive loading, and wherein the first and second cellular telephone bands are selected from the group consisting of an 850 MHz band, a 900 MHz band, an 1800 MHz band, a 1900 MHz band, and a 2170 MHz band. 
   
   
     7. Tunable multiport antenna circuitry comprising:
 a substantially planar radiating element; 
 a circuit board having a ground conductive path and first and second antenna feed conductive paths; 
 a ground electrical connecting structure that connects the ground conductive path to the radiating element and serves as a ground terminal for the radiating element; 
 a first feed electrical connecting structure that electrically connects the first feed conductive path on the circuit board to the radiating element at a first location and serves as a first feed terminal for the radiating element, wherein the first feed terminal and the ground terminal form a first antenna port through which antenna signals are transmitted and received; and 
 a second feed electrical connecting structure that electrically connects the second feed conductive path on the circuit board to the radiating element at a second location distinct from the first location and serves as a second feed terminal for the radiating element, wherein the second feed terminal and the second ground terminal form a second antenna port through which antenna signals are transmitted and received. 
 
   
   
     8. The tunable multiport circuitry defined in  claim 7  wherein at least one of the ground electrical connecting structure, the first feed electrical connecting structure, and the second feed electrical connecting structure comprises a spring-loaded pin. 
   
   
     9. The tunable multiport circuitry defined in  claim 7  wherein at least one of the ground electrical connecting structure, the first feed electrical connecting structure, and the second feed electrical connecting structure comprises a piece of bent conductor that serves as a spring. 
   
   
     10. The tunable multiport circuitry defined in  claim 7  wherein at least one of the ground electrical connecting structure, the first feed electrical connecting structure, and the second feed electrical connecting structure comprises a piece of bent conductor formed as an integral part of the radiating element that serves as a spring and that is soldered to one of the conductive paths on the circuit board. 
   
   
     11. The tunable multiport circuitry defined in  claim 7  wherein the circuit board has a third feed conductive path, the circuitry further comprising:
 a third feed electrical connecting structure that electrically connects the third feed conductive path on the circuit board to the radiating element at a third location distinct from the first and second locations and that serves as a third feed terminal for the radiating element.

Description:
BACKGROUND 
   This invention can relate to antennas, and more particularly, to compact tunable antennas used in wireless handheld electronic devices. 
   Wireless handheld devices, such as cellular telephones, contain antennas. As integrated circuit technology advances, handheld devices are shrinking in size. Small antennas are therefore needed. 
   A typical antenna for a handheld device is formed from a metal radiating element. The radiating element may be fabricated by patterning a metal layer on a circuit board substrate or may be formed from a sheet of thin metal using a foil stamping process. These techniques can be used to produce antennas that fit within the tight confines of a compact handheld device. 
   Modern handheld electronic devices often need to function over a number of different communications bands. For example, quad-band cellular telephones that use the popular global system for mobile (GSM) communications standard need to operate at four different frequencies (850 MHz, 900 MHz, 1800 MHz, and 1900 MHz). 
   Although multi-band operation is desirable, it is difficult to design a compact antenna that functions satisfactorily over a wide frequency range. This is because small antennas tend to operate over narrow frequency ranges due to the small dimensions of their radiating elements. 
   Antennas with tunable capacitive loading have been developed in an attempt to address the need for compact multi-band antennas. By varying the amount of capacitive loading that is applied to the radiating element, the resonant frequency of the antenna can be adjusted. This allows an antenna with a relatively narrow frequency range to be tuned sufficiently to cover more than one band. 
   The adjustable capacitive loading that is placed on this type of antenna leads to unwanted power loss. As a result, capacitively-tuned antennas tend to exhibit less-than-optimal efficiencies. 
   It would be desirable to be able to provide ways in which to improve the performance of tunable antennas for handheld electronic devices. 
   SUMMARY 
   In accordance with the present invention, tunable multiport antennas are provided. Handheld devices that use the tunable multiport antennas and methods for calibrating and using the tunable multiport antennas are also provided. 
   A tunable multiport antenna can have a ground terminal and multiple feed terminals. Each feed terminal can be used with the ground terminal to form a separate antenna port. By selecting which antenna port is active at a given time, the antenna&#39;s operating frequencies can be tuned. 
   Tunable multiport antennas contain radiating elements. The radiating elements may be formed, for example, by a foil stamping process or by patterning a conductive layer on a substrate such as a printed circuit board or flex circuit. Each radiating element can resonate at a fundamental frequency range. The dimensions of the radiating element may be chosen to align the antenna&#39;s fundamental operating frequency range with at least one communications band. If desired, the radiating element may also be used at one or more harmonic frequency ranges. 
   The radiating element can be coupled to a printed circuit board on which electronic components for a handheld electronic device are mounted. The printed circuit board can contain conductive traces that connect the components to the ground and feed terminals of the antenna. Electrical connecting structures, such as springs and spring-loaded pins, can be used to electrically connect the conductive traces on the printed circuit board to the ground and feeds of the radiating element. 
   Handheld electronic devices can contain radio-frequency transceivers and switching circuitry. The radio-frequency transceivers can have input-output paths that are used to transmit and receive signals associated with different communications bands. The switching circuitry can selectively connects the input-output paths to the ports of the antenna. During operation of a handheld electronic device, control circuitry on the device can direct the switching circuitry to activate a desired one of the antenna ports. By selecting which antenna port is active, the control circuitry can tune the antenna so that one or more of the antenna&#39;s operating frequency ranges aligns with one or more desired communications bands. 
   Because the antenna can be tuned, it is not necessary to enlarge the dimensions of the radiating element to broaden the bandwidth of the radiating element&#39;s resonant frequencies. This allows the antenna to be implemented with a small footprint. The use of multiple feeds in the radiating element permits tuning without the use of adjustable capacitive loading, which reduces reactive antenna losses and enhances antenna efficiency. 
   Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an illustrative circuit board to which a multi-port antenna is mounted in accordance with the present invention. 
       FIG. 2  is a graph in which the return loss of the antenna of  FIG. 1  has been plotted as a function of frequency in accordance with the present invention. 
       FIG. 3  is a schematic diagram of an illustrative handheld device containing a tunable antenna in accordance with the present invention. 
       FIGS. 4-14  are diagrams of illustrative antenna radiating elements having multiple feeds that can be selected for tuning in accordance with the present invention. 
       FIG. 15  is a side view of an illustrative printed circuit board showing how vias can be used to connect the upper and lower surfaces of the printed circuit board to form a ground plane for an antenna of the type show in  FIG. 1  in accordance with the present invention. 
       FIG. 16  is a perspective view of an illustrative portion of a circuit board assembly showing how a radiating element with an integral spring may be used to make contact between to a pad on a printed circuit board of the type shown in  FIG. 15  in accordance with the present invention. 
       FIG. 17  is a cross-sectional side view of an illustrative spring-loaded pin that may be used to connect an antenna&#39;s radiating element to a circuit board in accordance with the present invention. 
       FIG. 18  is a cross-sectional side view showing use of an illustrative spring-loaded pin that is soldered to a radiating element to make contact with a printed circuit board in accordance with the present invention. 
       FIG. 19  is a cross-sectional side view showing use of an illustrative spring-loaded pin that is soldered to a printed circuit board to make contact with an antenna&#39;s radiating element in accordance with the present invention. 
       FIG. 20  is a cross-sectional side view showing use of an illustrative spring to make contact between a radiating element and a printed circuit board in accordance with the present invention. 
       FIG. 21  is a cross-sectional side view showing use of an illustrative spring that is attached to a printed circuit board to make contact with a post of a radiating element formed from flexible circuit board material in accordance with the present invention. 
       FIGS. 22 and 23  are cross-sectional side views showing use of an illustrative floating spring-loaded pin to make contact between a radiating element and a printed circuit board in accordance with the present invention. 
       FIG. 24  is a circuit diagram showing how illustrative switches may be used to selectively connect a radio-frequency (RF) transceiver integrated circuit operating in two frequency bands to two different antenna feeds in accordance with the present invention. 
       FIG. 25  is a graph showing the return loss of an illustrative radiating element versus frequency as the circuitry of  FIG. 24  selects between each of two different antenna feeds on the radiating element in accordance with the present invention. 
       FIG. 26  is a circuit diagram showing how illustrative switches may be used to selectively connect a radio-frequency (RF) transceiver integrated circuit operating in three frequency bands to two different antenna feeds in accordance with the present invention. 
       FIG. 27  is a graph showing the return loss of an illustrative radiating element versus frequency as the circuitry of  FIG. 26  selects between each of two different antenna feeds on the radiating element in accordance with the present invention. 
       FIG. 28  is a circuit diagram showing how illustrative switches and a passive antenna duplexer may be used to selectively connect a radio-frequency (RF) transceiver integrated circuit operating in three frequency bands to two different antenna feeds in accordance with the present invention. 
       FIG. 29  is a graph showing the return loss of an illustrative radiating element versus frequency as the circuitry of  FIG. 28  selects between each of two different antenna feeds on the radiating element in accordance with the present invention. 
       FIG. 30  is a circuit diagram showing how illustrative switches and a passive antenna diplexer may be used to selectively connect a radio-frequency (RF) transceiver integrated circuit operating in three frequency bands to two different antenna feeds in accordance with the present invention. 
       FIG. 31  is a graph showing the return loss of an illustrative radiating element versus frequency as the circuitry of  FIG. 30  selects between each of two different antenna feeds on the radiating element in accordance with the present invention. 
       FIG. 32  is a diagram showing how transmitting and receiving subbands may be coupled to an antenna feed using an illustrative switch in accordance with the present invention. 
       FIG. 33  is a diagram showing how transmitting and receiving subbands may be coupled to an antenna feed using an illustrative duplexer in accordance with the present invention. 
       FIG. 34  is a diagram showing how an illustrative RF transceiver integrated circuit with five bands can be selectively connected to two different antenna feeds using switching circuitry made up of two switches in accordance with the present invention. 
       FIG. 35  is a diagram showing the return loss of an illustrative radiating element versus frequency as the circuitry of  FIG. 34  selects between each of the two different antenna feeds in accordance with the present invention. 
       FIG. 36  is a diagram showing how an illustrative RF transceiver integrated circuit with four bands can be selectively connected to two different antenna feeds using two diplexers in accordance with the present invention. 
       FIG. 37  is a diagram showing the return loss of an illustrative radiating element versus frequency as the switching circuitry of  FIG. 36  selects between each of the two different antenna feeds in accordance with the present invention. 
       FIG. 38  is a diagram showing how an illustrative RF transceiver integrated circuit with five bands can be selectively connected to three different antenna feeds using two diplexers and a duplexer in accordance with the present invention. 
       FIG. 39  is a diagram showing the return loss of an illustrative radiating element versus frequency as the switching circuitry of  FIG. 38  selects between each of the three different antenna feeds in accordance with the present invention. 
       FIG. 40  is a diagram of illustrative handheld electronic device circuitry including control circuitry that transmits and receives data, an RF module containing an RF transceiver integrated circuit and switching circuitry, and an antenna module having a multi-feed radiating element in accordance with the present invention. 
       FIG. 41  is a diagram showing how an illustrative tester can be used to calibrate a circuit board containing a multi-feed antenna in accordance with the present invention. 
       FIG. 42  is a cross-sectional side view of an illustrative RF switch connector for an RF module when the RF module is in normal operation in accordance with the present invention. 
       FIG. 43  is a cross-sectional side view of an illustrative RF switch connector for an RF module when the RF module is being calibrated using a test probe in accordance with the present invention. 
       FIG. 44  is a flow chart of illustrative steps involved in calibrating and using a handheld electronic device having a multi-feed antenna in accordance with the present invention. 
   

   DETAILED DESCRIPTION 
   The present invention can relate to tunable antennas for portable electronic devices, such as handheld electronic devices. The invention can also relate to portable devices that contain tunable antennas and to methods for testing and using such devices and antennas. 
   A tunable antenna in accordance with the invention can have a radiating element with multiple antenna feeds and a ground. The radiating element may be formed using any suitable antenna structure such as a patch antenna structure, a planar inverted-F antenna structure, a helical antenna structure, etc. 
   The portable electronic devices may be small portable computers such as those sometimes referred to as ultraportables. With one particularly suitable arrangement, the portable electronic devices are handheld electronic devices. The use of handheld devices is generally described herein as an example. 
   The handheld devices may be, for example, cellular telephones, media players with wireless communications capabilities, handheld computers (also sometimes called personal digital assistants), remote controllers, and handheld gaming devices. The handheld devices of the invention may also be hybrid devices that combine the functionality of multiple conventional devices. Examples of hybrid handheld devices include a cellular telephone that includes media player functionality, a gaming device that includes a wireless communications capability, a cellular telephone that includes games and email functions, and a handheld device that receives email, supports mobile telephone calls, and supports web browsing. These are merely illustrative examples. Any suitable device may include a tunable multi-feed antenna, if desired. 
   Illustrative antenna and control circuitry  10  that may be used in a handheld device in accordance with the invention is shown in  FIG. 1 . Circuitry  10  can include control circuitry  28 . Control circuitry  28  may include one or more integrated circuits such as microprocessors, microcontrollers, digital signal processors, field programmable gate arrays, power amplifiers, and application-specific integrated circuits. Control circuitry  28  may also include passive RF components such as duplexers, diplexers, and filters. 
   Control circuitry  28  may be mounted to one or more printed circuit boards  30  or other suitable mounting structures. Circuit board  30  may be, for example, a dual-sided circuit board containing patterned conductive traces. 
   Control circuitry  28  can send and receive RF signals. The RF signals may be provided to an antenna module. The antenna module can contain a radiating element  12 . Radiating element  12  may be formed from a highly-conductive material, such as copper, gold, alloys containing copper and other metals, high-conductivity non-metallic conductors (e.g., high-conductivity organic-based materials, high-conductivity superconductors, highly-conductive liquids), etc. In the example of  FIG. 1 , the radiating element  12  can have a thin planar profile, which facilitates placement of the radiating element  12  within a handheld device. The use of a radiating element with a planar structure is, however, merely illustrative. The radiating element  12  may be formed in any suitable shape. 
   In the  FIG. 1  example, slot  14  can be formed in radiating element  12 , which increases the effective length of the radiating element  12 , while maintaining a compact footprint. Radiating element  12  may be formed using any suitable manufacturing technique. With one suitable arrangement, the so-called foil stamping method can be used to form radiating element  12 . With foil stamping techniques, a foil stamping machine is used to generate numerous radiating elements from a thin copper foil. Another suitable technique for forming radiating element can involve printing or etching the antenna pattern onto a fixed or flexible substrate. Flexible substrates that may be used during these patterning processes include so-called flex circuits (e.g., circuits formed from metals such as copper that are layered on top of flexible substrates such as polyimide). If desired, other techniques may be used to form radiating elements  12 . 
   The radiating element  12  can have a ground signal terminal and two or more corresponding positive signal terminals. The positive signal terminals can be called antenna feeds. In the example of  FIG. 1 , radiating element  12  can have three elongated portions  16 ,  18 , and  20 . Elongated portion  16  may serve as ground. Elongated portion  18  may serve as a first feed. Elongated portion  20  may serve as a second feed. In general, there may be any suitable number of feeds in the antenna (e.g., two feeds, three feeds, four feeds, more than four feeds, etc.). 
   Control circuitry  28  may include input-output terminals, such as ground input-output terminal  32  and positive input-output terminals  34  and  36 . Conductive paths such as paths  22 ,  24 , and  26  may be used to electrically connect the input-output terminals of control circuitry  28  to radiating element  12 . Paths  22 ,  24 , and  26  may be patterned conductive traces (e.g., metal traces) formed on printed circuit board  30 . Paths  24  and  26  may be used to electrically connect positive input-output terminals  34  and  36  to elongated portions  18  and  20 , respectively. A path such as path  22  may be used to connect the ground input-output terminal  32  to the ground portion  16  of radiating element  12 . If desired, the upper and lower portions of printed circuit board  30  may also be connected to ground. The elongated portions  16 ,  18 , and  20  may be soldered or otherwise electrically connected to paths  22 ,  24 , and  26 . 
   In the example of  FIG. 1 , the elongated portions  16 ,  18 , and  20  are shown as being formed as an integral portion of radiating element  12  and paths  22 ,  24 , and  26  are shown as being formed from circuit board traces. This is merely one suitable arrangement for connecting the ground and feeds of the radiating element  12  to the circuitry of the handheld device. Other suitable arrangement include contact arrangements based on external spring-loaded pins and spring connectors. Regardless of the particular type of arrangement that is used to convey signals into and out of the radiating element, the radiating element structure that is associated with ground is commonly referred to as the antenna&#39;s and radiating element&#39;s ground pin, ground terminal, or ground and the radiating element structure that is associated with positive antenna signals is commonly referred to as the antenna&#39;s and radiating element&#39;s feed pin, feed terminal, or feed. 
   The antenna formed from radiating element  14  has a resonant frequency f 0  at which it can transmit and receive signals. The operating frequency range surrounding f 0  is sometimes referred to as the fundamental band or fundamental operating frequency range of the antenna. If, as an example, f 0  is at 850 MHz, the antenna&#39;s fundamental frequency range can be used to cover a 850 MHz communications band. Antennas also generally resonate at higher frequencies that are harmonics of f 0 . With this type of arrangement, an antenna can cover two or more bands. For example, an antenna may be designed to cover both the 850 MHz band (using the antenna&#39;s fundamental frequency range centered on f 0 ) and the 1800 MHz band (using a harmonic frequency range). 
   The bandwidth associated with an antenna&#39;s operating frequency is influenced by the geometry of the radiating element  12 . Antennas that are compact tend to have narrow bandwidths. Unless the bandwidth of the antenna is widened (e.g., by increasing its physical size), the antenna will not be able to cover nearby bands without tuning. 
   As an example, consider the GSM cellular telephone standard, which uses bands at 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz. These bands may have bandwidths of about 70-80 MHz (for the 850 MHz and 900 MHz bands), 170 MHz (for the 1800 MHz band), and 140 MHz (for the 1900 MHz band). Each band may contain two associated subbands for transmitting and receiving data. For example, in the 850 MHz band, a subband that extends from 824 to 849 MHz may be used for transmitting data from a cellular telephone to a base station and a subband that extends from 869 to 894 MHz may be used for receiving data from a base station. The 850 MHz and 1900 MHz bands may be used in countries such as the United States. The 900 MHz and 1800 MHz may be used in countries such as the European countries. 
   A compact antenna that is designed to cover the 850 MHz band may have a harmonic that allows it to simultaneously cover a higher band (e.g., 1900 MHz), but a compact antenna that has a narrow bandwidth will not be able to cover both the 850 MHz and 900 MHz bands unless it is tuned. 
   In accordance with the present invention, control circuitry  28  may be used to select between different feeds to tune the antenna formed from radiating element  12 . When, for example, signals are transmitted or received using ground terminal  32  and input-output terminal  34 , the antenna covers one band. When signals are transmitted on received using ground terminal  32  and input-output terminal  36 , the antenna covers a different band. 
   Each feed (and its associated ground) may serve as an antenna port. An antenna such as an antenna formed from radiating element  12  of  FIG. 1  therefore can have multiple ports and can be tuned by proper port selection. The control circuitry  28  can be used to determine which port is used. When access to a particular band is desired, the control circuitry  28  ensures that the proper port is active. By using multiple ports, a compact antenna with potentially narrow resonances can be tuned to cover all bands of interest. 
   A graph containing an illustrative plot of return loss versus frequency for a tunable multi-port antenna in accordance with the present invention is shown in  FIG. 2 . Return loss is at a minimum at the antenna&#39;s fundamental operating frequency range. No harmonic frequency ranges are shown in  FIG. 2 . 
   When signals are transmitted and received through a first antenna port (i.e., ground terminal  32 , path  22 , and radiating element extension  16  and positive input-output terminal  34 , path  24 , and radiating element extension  18 ), the antenna covers the frequency range centered at frequency f a , as shown by the solid line in  FIG. 2  When signals are transmitted and received through a second antenna port (i.e., ground terminal  32 , path  22 , and radiating element extension  16  and positive input-output terminal  36 , path  26 , and radiating element extension  20 ), the antenna covers the frequency range centered at frequency f b , as shown by the dashed line in  FIG. 2 . This allows the control circuitry  28  to tune the antenna as needed. When it is desired to send or receive data in the f a  range, the control circuitry  28  uses the first port. When the second port is used, the antenna&#39;s response is tuned to higher frequencies, so that the antenna covers a range of frequencies centered at f b . 
   By using intelligent port selection, the coverage of an antenna can be extended to cover all frequency bands of interest. Because compact radiating elements tend to have small sizes, an antenna that is tuned by selecting a desired antenna port can be made more compact than would otherwise be possible, while still ensuring that all desired bands are covered. Moreover, tuning through the use of port selection can be more efficient than antenna tuning through adjustable capacitive loading schemes. Such capacitive loading schemes introduce reactive losses, which reduce antenna efficiency. An antenna with multiple feeds need not be tuned using variable capacitive loading because tuning can be performed through proper port selection. 
   A schematic diagram of an illustrative handheld electronic device  38  containing a tunable multi-port antenna is shown in  FIG. 3 . Handheld device  38  may be a mobile telephone, a mobile telephone with media player capabilities, a handheld computer, a game player, a combination of such devices, or any other suitable portable electronic device. 
   As shown in  FIG. 3 , handheld device  38  may include storage  40 . Storage  40  may include one or more different types of storage such as hard disk drive storage, nonvolatile memory (e.g., FLASH or electrically-programmable-read-only memory), volatile memory (e.g., battery-based static or dynamic random-access-memory), etc. 
   Processing circuitry  42  may be used to control the operation of device  38 . Processing circuitry  42  may be based on a processor such as a microprocessor and other suitable integrated circuits. 
   Input-output devices  44  may allow data to be supplied to device  38  and may allow data to be provided from device  38  to external devices. Input-output devices can include user input-output devices  46  such as buttons, touch screens, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, cameras, etc. A user can control the operation of device  38  by supplying commands through user input devices  46 . Display and audio devices  48  may include liquid-crystal display (LCD) screens, light-emitting diodes (LEDs), and other components that present visual information and status data. Display and audio devices  48  may also include audio equipment such as speakers and other devices for creating sound. Display and audio devices  48  may contain audio-video interface equipment such as jacks for external headphones and monitors. 
   Wireless communications devices  50  may include communications circuitry such as RF transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, passive RF components, antennas such as the multiport antenna of  FIG. 1 , and other circuitry for generating RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications). 
   The device  38  can communicate with external devices such as accessories  52  and computing equipment  54 , as shown by paths  56 . Paths  56  may include wired and wireless paths. Accessories  52  may include headphones (e.g., a wireless cellular headset or audio headphones) and audio-video equipment (e.g., wireless speakers, a game controller, or other equipment that receives and plays audio and video content). Computing equipment  54  may be a server from which songs, videos, or other media are downloaded over a cellular telephone link or other wireless link. Computing equipment  54  may also be a local host (e.g., a user&#39;s own personal computer), from which the user obtains a wireless download of music or other media files. 
   As described in connection with  FIG. 1 , the multiport antenna used in the handheld device can be formed from any suitable radiating element  12 . An example of a radiating element  12  that is formed from a rectangular patch antenna structure is shown in  FIG. 4 . The antenna structure of  FIG. 4  and the other radiating element structures are preferably about one quarter of a wavelength in size (e.g., several centimeters for most cellular telephone wavelengths). 
   The radiating element  12  of  FIG. 4  may have a ground terminal  16 , a first feed  18 , a second feed  20 , and potentially more feeds (shown by dotted feed structure  21 ). In general, any radiating element  12  may have more than two feeds, but only the radiating element  12  of  FIG. 4  shows the additional feeds to avoid over-complicating the drawings. 
   Different fundamental resonant frequencies are associated with each of the different antenna ports and are influenced by the geometry of the radiating element  12 . As shown in  FIG. 4 , when feed  18  is used, there is an inductive path in the antenna between feed  18  and ground  16 . This path is shown schematically by dotted line  60 . When feed  20  is used, there is a different inductive path in the antenna, shown by dotted line  58 . Inductances L 1  and L 2  are associated with paths  60  and  58 , respectively. The inductance L 2  is generally larger than the inductance L 1 , so the port formed using feed  20  resonates at a higher frequency (e.g., frequency f b  of  FIG. 2 ) than the port formed using feed  18  (e.g., frequency f a  of  FIG. 2 ). 
   An illustrative radiating element  12  that is formed from a rectangular patch antenna structure containing a slot  14  is shown in  FIG. 5 . Because of the presence of slot  14 , the antenna of  FIG. 5  will exhibit harmonics that are shifted with respect to the harmonics of the patch antenna structure of  FIG. 4 . This allows the antenna designer to place harmonics at desired communications bands. 
   If desired, antenna ports may be formed on the shorter side of a rectangular patch. An illustrative structure of the type shown in  FIG. 1  in which feeds have been placed on the shorter size of the rectangular patch is shown in  FIG. 6 . 
   Another illustrative radiating element  12  is shown in  FIG. 7 . With the arrangement of  FIG. 7 , the rectangular patch structure has a cut-away portion  68 . The cut-away portion  68  may be formed to accommodate a cellular telephone camera, a button, a microphone, speaker, or other component of the handheld device. Ports may be formed on the long side of the element  12  (e.g., using ground  16  and feeds  18  and  20 ) or on the short side of element  12  (e.g., using ground  16  and feeds  18   a  and  20   a ). As shown in  FIG. 8 , the cut-away portion  68  need not be formed in the center of the radiating element  12 . 
     FIG. 9  shows how the sides of a radiating element may be bent downwards. Portions of the radiating element  12  such as portions  70  and  72  may be formed during a foil stamping process or by using a flex circuit. Portions  70  and  72  may serve as a fixed source of capacitive loading. Using bent-down portions in this type of arrangement tends to decrease the footprint of the radiating element for a given operating frequency. If desired, other forms of capacitive loading may be used with radiating element. Capacitive loading can be used with the patch antenna structure of  FIG. 7  (as shown in the example of  FIG. 9 ) or with any other suitable radiating element structure. 
   If desired, a radiating element  12  may be formed from a flex circuit or other flexible substrate. In the example of  FIG. 10 , radiating element  12  is formed from a conductive element  62  that is formed in a serpentine pattern on flex circuit substrate  64 . After the serpentine pattern is formed on substrate  64 , the substrate  64  is curled to form the cylindrical shape of  FIG. 10 . The cylindrical antenna of  FIG. 10  has a ground  16  and two feeds  18  and  20 . 
   In the illustrative arrangement of  FIG. 11 , radiating element  12  is formed from a patch antenna having a serpentine slot  14 . In general, one or more slots of any suitable shape may be formed in the radiating element  12 . 
     FIG. 12  shows an illustrative arrangement for a radiating element  12  that is based on an L-shaped planar antenna arrangement. The radiating element  12  of  FIG. 12  has a ground  16  and feeds  18  and  20 . 
   In  FIG. 13 , the ground terminal  16  is formed using a separate conductor from the conductive element that contains feeds  18  and  20 . 
     FIG. 14  shows an illustrative radiating element  12  that is formed from a separate ground element  16  and serpentine element  66 . Feeds  18  and  20  are formed at different locations in the serpentine element  66 . 
   The radiating element structures show in FIGS.  1  and  4 - 14  are merely illustrative. In general, any suitable radiating element structures with multiple feeds may be used. 
   As shown in  FIG. 15 , a printed circuit board such as printed circuit board  30  of  FIG. 1  may have an upper surface of conductive material  74  and a lower surface of conductive material  76  separated by an insulating printed circuit board layer  78 . The upper and lower conductive surfaces may contain a patterned metal such as copper. The lower surface may be relatively unpatterned and may be used to form a ground plane. Ground wires on the upper surface may be connected to the lower surface ground plane using conductive vias  80 . When mounting the radiating element  12  to the printed circuit board  30 , the patterned conductors on the upper surface of printed circuit board  30  may be used to form electrical contact with the radiating element. 
   Electrical contact may be made using any suitable electrical connecting structures. In the example of  FIG. 16 , an elongated portion of radiating element  12  (e.g., a ground or feed element of the type shown in  FIG. 1 ) is shown as forming a spring  82 . When the antenna is mounted in proximity to the circuit board, the spring portion  82  presses against a conductive trace  84  on the upper surface  74  of circuit board  30 . This forms an electrical contact between trace  84  (which is connected to control circuitry  28  of  FIG. 1 ) and the radiating element  12 . 
   If desired, spring-loaded pins may be used to make electrical contact between a radiating element  12  and circuit board  30 . One commonly-available spring-loaded pin is the so-called pogo pin. A cross-sectional side view of a spring-loaded pin  86  is shown in  FIG. 17 . Pin  86  has a reciprocating member  88  with a head portion  90  that reciprocates within a hollow cylindrical pin housing  98 . A spring  92  bears against the inner surface  94  of pin housing  98  and the upper surface  96  of head  90 . When member  88  is withdrawn within housing  98 , spring  92  is compressed and biases reciprocating member  88  in direction  100 . This drives the tip  102  of member  88  against a conductive element such as a portion of a circuit board or a radiating element. 
     FIG. 18  shows an arrangement in which a spring-loaded pin  86  has been soldered to a radiating element  12  with solder  104 . The tip  102  of the pin presses against a conductor on the surface of circuit board  30 . 
   In the arrangement of  FIG. 19 , the spring-loaded pin  86  has been soldered to a circuit board  30  and is pressing upward against the radiating element  12 , so that the tip  102  of reciprocating member  88  makes electrical contact with the radiating element. 
     FIG. 20  shows an arrangement in which a spring  108  has been soldered to a circuit board  30  with solder  106 . A portion  112  of radiating element  12  has been bent downward. The portion  112  of radiating element  12  may be formed during a metal foil stamping process (as an example). As shown in  FIG. 20 , spring  108  is compressed and bears against the portion  112 , thereby forming electrical contact between radiating element  12  and circuit board  30 . 
   The arrangement of  FIG. 21  is similar to the arrangement of  FIG. 20 , but involves forming an electrical connection to a radiating element  12  that is fabricated from a flex circuit. The radiating element  12  has a post  110 . As shown in  FIG. 21 , a spring  108  that has been soldered to circuit board  30  with solder  106  bears against post  110  to form electrical contact. 
   The pins and springs of  FIGS. 18 ,  19 ,  20 , and  21  need not be soldered to the circuit board or radiating element  12 . Arrangements in which the connecting electrical structure is not soldered are said to be floating.  FIGS. 22 and 23  show floating pin arrangements in which pin  86  forms an electrical connection between radiating element  12  and circuit board  30 . In the arrangement of  FIG. 22 , the tip  102  of pin  86  presses against the radiating element  12 . In the arrangement of  FIG. 23 , the tip  102  of pin  86  presses downward against a conductor on circuit board  30 . 
   Any suitable circuit architecture may be used to interconnect the control circuitry  28  with the feeds of the antenna and radiating element  12 . 
   Consider, as an example, the arrangement of FIG.  24 . As shown in  FIG. 24 , an RF transceiver integrated circuit  114  is connected to ground  16 . RF transceiver integrated circuit  114  is also connected to two antenna feeds  18  and  20  using input-output data paths  115  and switching circuitry formed from switches  116 . Switches  116  may be formed from PIN diodes, high-speed field-effect transistors (FETs), or any other suitable switch components. The switches for each feed are complementary and work in tandem. The state of each switch is the inverse of the other. When switch SW 1  is on, switch SW 2  is off and a first antenna port is active while a second antenna port is inactive. When switch SW 1  is off, switch SW 2  is on and the first antenna port is inactive while the second antenna port is active. Using this type of arrangement ensures that only one feed is active at a time. Feed 1  is active and feed 2  is inactive when switch SW 1  is on and switch SW 2  is off. Feed 2  is active and feed 1  is inactive when switch SW 2  is on and switch SW 1  is off. 
   The graph of  FIG. 25  shows the frequency response of the radiating element  12  in two conditions. The solid line shows the return loss of the radiating element at its fundamental operating frequency range when the first port is active. In this configuration, the antenna is tuned so that it operates at the frequency f a . The dashed line in  FIG. 25  shows the return loss of the radiating element when the second port is active. In this configuration, the antenna is tuned so that it operates at frequency f b . 
   In the arrangement of  FIG. 26 , switch SW 1  may handle two different bands (f a  and f b ), whereas switch SW 2  may handle frequency band f c . Switch SW 1  has three states. In its first state, input-output signal path  118  is connected to feed 1  and the antenna operates at frequency f a , as shown in  FIG. 27 . In its second state, input-output signal path  120  is connected to feed 1  and the antenna operates in band f b . As described in connection with  FIG. 24 , switch SW 2  is off whenever switch SW 1  is on. When it is desired to tune the antenna, the control circuitry  28  places switch SW 1  in a third state in which lines  118  and  120  are disconnected from feed 1  (i.e., switch SW 1  is off). When switch SW 1  is turned off, switch SW 2  is turned on, so the antenna operates at shifted fundamental frequency f c  ( FIG. 27 ). 
   As shown in  FIGS. 28 and 29 , passive RF components such as duplexers and diplexers may be used to couple RF transceiver  114  to the antenna feeds. A duplexer can be used to combine or separate RF signals that are in adjacent bands (e.g., 850 MHz and 900 MHz). A diplexer can be used to combine or separate RF signals that are in distant bands (e.g., 850 MHz and 1800 MHz). 
   As shown in  FIG. 28 , duplexer  122  may be coupled between data paths  118  and  120  and switch SW 1 . Switch SW 2  is coupled between data path  126  and feed 2 . When it is desired to use feed 1 , switch SW 1  is turned on and switch SW 2  is turned off. This tunes the antenna so that it operates according to the solid line of  FIG. 29 . In this state, RF transceiver  114  can use paths  118  and  120  to transmit and receive in either frequency band f a  or frequency band f b , because the radiating element  12  of the antenna is designed to have a sufficiently large bandwidth in its fundamental operating frequency range to handle the adjacent bands f a  and f b . When it is desired to tune the antenna by using feed 2 , switch SW 1  is turned off and switch SW 2  is turned on. In this state, path  126  is connected to feed 2  and transceiver  114  can transmit and receive signals using band f c , as shown by the dotted line in  FIG. 29 . 
   In the arrangement of  FIG. 30 , a diplexer  124  is used in place of a duplexer. The radiating element  12  in this scenario is designed to have a harmonic at f b . Because a diplexer  124  is being used, the signals associated with paths  118  and  120  must be more widely separated than in the duplexer arrangement of  FIG. 28 . As shown by the solid line in  FIG. 31 , when feed 1  is switched into use by turning on SW 1  and turning off SW 2 , transceiver  114  can use paths  118  and  120  to transmit and receive in either fundamental frequency band f a  or harmonic frequency band f b . When it is desired to tune the antenna by using feed 2 , switch SW 1  is turned off and switch SW 2  is turned on. In this state, path  126  is connected to feed 2  and transceiver  114  can transmit and receive signals using band f c , as shown by the dotted line in  FIG. 31 . 
   The bands used in GSM communications each have two subbands, one of which contains channels for transmitting data and the other of which contains channels for receiving data. As shown in  FIG. 32 , a switch  116  can be used to connect an appropriate transmit or receive data path to its associated feed  128 . Paths  118   a  and  118   b  are connected to the RF transceiver. In GSM communications, signals are either transmitted or are received. Simultaneous transmission and reception is not permitted. When the RF transceiver has data to transmit, switch  116  connects the transmit line  118   a  to feed  128 . In receive mode, the switch  116  is directed to connect feed  128  to path  118   b . When it is desired to inactivate the feed  128 , switch  116  may be turned off. In the example of  FIG. 32 , paths  118   a  and  118   b  are labeled  850 T (850 MHz transmit) and  850 R (850 MHz receive). The same principal applies to all GSM bands. The input-output data paths connected to the RF transmitter  114  in  FIGS. 24 ,  26 ,  28 , and  30  are shown as single bidirectional paths rather than as separate transmit and receive paths to avoid over-complicating the drawings. 
   An arrangement in which a duplexer  122  may be used to couple an RF transceiver to a feed  128  is shown in  FIG. 33 . When incoming data is received on feed  128  or when outgoing data is being transmitted, switch  116  is on. Switch  116  is off when it is desired to tune the antenna by using a different feed. Duplexer  122  is frequency sensitive. Incoming data (e.g., on the  850 R subband) is routed to line  118   b  by the passive RF components in duplexer  122 . When outgoing data is transmitted on line  118   a , duplexer  122  routes those signals to line  128  via switch  116 . 
   When architectures of the type shown in  FIGS. 24 ,  26 ,  28 , and  30  are used for GSM-type communications, an active subband switching arrangement of the type shown in  FIG. 32  or a passive subband routing arrangement of the type shown in  FIG. 33  may be used. In either case, switching circuitry  116  is used to ensure that the appropriate antenna feed is active. 
   In some communications protocols such as those based on code division multiple access (CDMA) technology, signals can be transmitted and received simultaneously. There is therefore no need for a switch to actively switch between transmit and receive bands. Examples of communications schemes that use CDMA technology include CDMA cellular telephone communications and 3G data communications over the 2170 MHz band (commonly referred to as UMTS or Universal Mobile Telecommunications System). With CDMA-based arrangements, a duplexer arrangement of the type shown in  FIG. 33  may be used to separate transmitting and receiving frequencies from each other. 
   Some handheld devices need to cover many bands. An example of an arrangement that may be used to cover five bands (e.g., the four GSM bands plus the UMTS band) using a two port antenna is shown in  FIG. 34 . A graph showing the placement of each of the bands is shown in  FIG. 35 . The antenna is designed to have a fundamental operating frequency range  128  at about 850-900 MHz and a harmonic operating frequency range  130  at about 1800-1900. When switch SW 1  is on and switch SW 2  is off, feed 1  is active and the antenna&#39;s response is as shown by the solid line in  FIG. 35 . The antenna is designed to have a relatively broad bandwidth at its fundamental and harmonic operating frequencies. As a result, the antenna covers both the 850 MHz and 900 MHz GSM bands in the fundamental operating frequency range  128  and covers both the 1800 MHz and 1900 MHz GSM bands using the harmonic operating frequency range  130 . When switch SW 2  is on and switch SW 1  is off, feed  2  is active and the antenna is tuned. This shifts the harmonic operating frequency range  130  to a higher frequency, so that it covers the UMTS band at 2170 MHz. 
   An example of an arrangement that may be used to cover four bands (e.g., the four GSM bands) using a two port antenna is shown in  FIG. 36 . Diplexers  124  are used to couple RF transceiver  114  to switching circuitry  116 . One diplexer  124  handles the 850 MHz and 1800 MHz bands while the other diplexer  124  handles the 900 MHz and 1900 MHz bands. A graph showing the placement of each of the bands is shown in  FIG. 37 . The antenna is designed to have a fundamental operating frequency range  128  at about 850 MHz and a harmonic operating frequency range  130  at about 1800. When switch SW 1  is on and switch SW 2  is off, feed 1  is active and the antenna&#39;s response is as shown by the solid line in  FIG. 37 . The antenna has a narrow bandwidth that covers a single band at each resonant frequency. 
   As shown by the solid line in  FIG. 37 , when feed 1  is used, the antenna can cover both the 850 MHz and 1800 MHz bands. When it is desired to tune the antenna, switches  116  are adjusted so that feed 2  is used. This shifts both the fundamental operating range  128  and the harmonic operating frequency range  130  to higher frequencies, so as to cover the 900 MHz and 1900 MHz bands, respectively, as shown by the dashed line in  FIG. 37 . 
   An example of an arrangement that may be used to cover five bands (e.g., the four GSM bands and the UMTS band) using a three port antenna is shown in  FIG. 38 . Diplexers  124  are used to couple RF transceiver  114  to switching circuitry  116 . One diplexer  124  handles the 850 MHz and 1800 MHz bands while the other diplexer  124  handles the 900 MHz and 1900 MHz bands. The placement of each of the bands is shown in the graph of  FIG. 39 . When feed 1  is used, the antenna is has a fundamental operating frequency range  128  at about 850 MHz and a harmonic operating frequency range  130  at about 1800 MHz. When switch SW 1  is on and switches SW 2  and SW 3  are off, feed 1  is active and the antenna&#39;s response is as shown by the solid line in  FIG. 39 . 
   As shown by the solid line in  FIG. 39 , when feed 1  is used, the antenna covers both the 850 MHz and 1800 MHz bands. Due to the relatively narrow bandwidth of the antenna, adjacent bands are not covered without tuning. When it is desired to tune the antenna to cover the 900 MHz and 1900 MHz bands, switches  116  are adjusted so that feed 2  is used. This shifts both the fundamental operating range  128  and the harmonic operating frequency range  130  to higher frequencies, so as to cover the 900 MHz and 1900 MHz bands, respectively, as shown by the dashed line in  FIG. 39 . 
   When it is desired to tune the antenna to cover the 2170 MHz band, switches  116  are adjusted so that feed 3  is switched into use. As a result, the fundamental operating range  128  and the harmonic operating frequency range  130  are shifted to higher frequencies. With this antenna tuning configuration, the harmonic operating frequency range  130  covers the 2170 MHz band, as shown by the dot-and-dashed line in  FIG. 39 . 
     FIG. 40  shows details of an arrangement of the type described in  FIG. 34  in which five bands are covered (e.g., the four GSM bands and the UMTS band) using two antenna ports. 
   Processing circuitry  42  can generate data to be transmitted and can provide this data to RF module  132  in wireless communications circuitry  50  using a path such as path  140 . Data that is received by the handheld device may be routed from RF module  132  to processing circuitry  42  via path  142 . Transceiver  114  can be coupled to radiating element  12  in antenna module  134  via feed 1 , feed 2 , and ground. Switching circuitry  116  can be used to regulate which antenna port is active. Switch SW 1  can be used to select a desired GSM signal path to connect to feed 1  when feed 1  is active and is used to disconnect feed 1  from the RF transmitter when feed 1  is inactive. Switch SW 2 , which is on when switch SW 1  is inactive, can used to seletively activate feed 2 . Switch SW 2  can receive transmitted signals from RF transceiver  114  and can deliver received signals to RF transceiver  114  through duplexer  122 , which can handle the transmit and receive subbands for a 2170 MHz UMTS band. 
   A power amplifier integrated circuit  136  may be used to boost outgoing signal levels. Power amplifier integrated circut  136  contains power amplifiers  138 . The power amplifiers may be provided as separate integrated circuits if desired. 
   A testing arrangement that may be used to calibrate an RF module  132  during the process of manufacturing a handheld device  38  is shown in  FIG. 41 . During testing, tester  144  can apply power and control signals to processing circuitry  42  using a path such as path  147 . The control signals may direct the processing circuitry  42  to transmit signals to antenna module  134 . Each feed can be calibrated in turn. Tester  144  has a cable and test probe that can be connected to either RF switch connector  152  (when the cable and probe are in the position indicated by line  148 ) or RF switch connector  156  (when the cable and probe are in the position indicated by line  150 ). During testing, the probe taps into the signals that would otherwise be transmitted over antenna module  134 . 
   RF switch connectors  152  and  156  have two operating conditions. A cross-section of an illustrative RF switch connector  166  is shown in  FIGS. 42 and 43 . When no test probe is inserted, as shown in  FIG. 42 , input  160  is connected to output  162  via conductor  164 . When the tip of a test probe  168  is inserted into switch connector  166 , conductor  164  is pressed downwards, which opens the circuit between conductor  164  and output  162  and electrically connects input  160  to the test probe  168 . 
   RF switch connector  152  may be used to tap into signals that would normally pass from data path  154  to feed 1 , whereas RF switch connector  156  may be used to tap into signals that would normally pass from data path  158  to feed 2 . During calibration, tester  144  measures the signal strenth received on each feed for a variety of output power settings. Using curve fitting techniques, tester  144  determines which calibration settings should be stored in the circuitry  10 . The calibration settings are loaded into non-volatile memory  40  such as flash memory over a path such as path  146 . Later, during normal operation, processing circuitry  42  uses the stored calibration settings to make calibrating adjustments to the output signal levels of the RF module  132 . 
   Illustrative steps involved in testing and fabricating handheld devices with tunable multi-port antennas are shown in  FIG. 44 . 
   At step  170 , a circuit board assembly containing the RF moudule  132  and antenna module  134  can be fabricated. 
   At step  172 , tester  144  of  FIG. 41  may send control signals to processing circuitry  42  via path  147 . The control signals direct the processing circuitry  42  to use transceiver  114  and switching circuitry  116  to transmit suitable test signals to the antenna on feeds  18  and  20 . Each feed is excercised separately. To ensure accurate measurements, test signals may be transmitted using several different power settings while tester  144  gathers associated test measurements. 
   At step  174 , the tester  144  can process the test measurements (e.g., using curve-fitting routines) and generates corresponding calibration settings. The calibration settings indicate what adjustments need to be made by RF module  132  during normal operation to ensure that the transmitted RF power levels are accurate. 
   The tester  144  can store the calibration information in memory  40  at step  176 . With one suitable arrangement, the calibration information is stored in a non-volatile memory such as a flash memory to ensure that the calibration information will be retained in the event of a loss of power by the handheld electronic device  38 . 
   During steps  178  and  180 , the handheld electronic device  38  may be used by a user to place cellular telephone calls, to upload or download data over a 3G link, or to otherwise wirelessly transmit and receive data. 
   During step  178 , the processing circuitry  42  ( FIG. 41 ) retrieves the calibration settings data from memory  40  and uses the retrieved calibration settings to adjust the power output of the handheld device so that the output power is calibrated. The processing circuitry  42  calibrates each port separately, so the output power is accurate regardless of which antenna port is being used. 
   During step  180 , the user can transmit and receive data using the antenna. The processing circuitry  42  tunes the antenna as needed by selecting an appropriate antenna feed using switching circuitry  116 . 
   The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20060905
Publication Date: 20100302
Grant Date: 20100302
Priority Date: 20060905
Inventors: ZHANG ZHIJUN
CABALLERO RUBEN
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q5/371", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0442", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q9/0421", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q9/0442", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q5/371", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 38704484