Variable time, phase, and amplitude control device

A signal conditioning device includes a substrate including at least one transmission line integrated therewith, a power divider for receiving an input signal and dividing the input signal into a plurality of divided signals, a plurality of time delay paths, each of the time delay paths coupled to an output of the power divider to receive at least one of the divided signals, wherein at least one of the time delay paths is in signal communication with the at least one transmission line to define a time delay associated therewith, a control device in signal communication with at least one of the time delay paths and controlling at least one of a phase shift and an amplitude of at least one of the divided signals, and a power combiner for receiving the divided signals and combining the signals into an output signal.

STATEMENT REGARDING GOVERNMENT SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

FIELD OF THE INVENTION

The present invention generally relates to radio frequency (RF) signal conditioning. In particular, the invention is directed to a device for providing selective and variable control over a time delay, amplitude, and phase of an RF signal.

BACKGROUND OF THE INVENTION

Providing precision control over the time delay, amplitude and phase delay of a radio frequency (RF) signal is fundamental to many applications that require precision and programmable RF signal conditioning. These applications include wideband array beam formation and diversity aperture combining.

In conventional true time delay devices, a control of time delays and phase is not independent from each other. Changing the time delay affects the phase delay of the carrier of the signal. The coupling of time delay and phase delay creates complexity at the system level, and is not desired for applications that require advanced signal conditioning techniques.

It would be desirable to develop a signal conditioning device for providing selective, independent, and variable control over a time delay, amplitude, and phase of a radio frequency signal, wherein the device can be implemented using radio frequency integrated circuit technology.

SUMMARY OF THE INVENTION

Concordant and consistent with the present invention, a signal conditioning device for providing selective, independent, and variable control over a time delay, amplitude, and phase of a radio frequency signal, wherein the device can be implemented using radio frequency integrated circuit technology, has surprisingly been discovered.

In one embodiment, a signal conditioning device comprises: a substrate including at least one transmission line integrated therewith; a power divider for receiving an input signal and dividing the input signal into a plurality of divided signals; a plurality of time delay paths, each of the time delay paths coupled to an output of the power divider to receive at least one of the divided signals, wherein at least one of the time delay paths is in signal communication with the at least one transmission line to define a time delay associated therewith; a control device in signal communication with at least one of the time delay paths and controlling at least one of a phase shift and an amplitude of at least one of the divided signals; and a power combiner for receiving the divided signals and combining the signals into an output signal.

In another embodiment, a signal conditioning device comprises: a substrate including at least one transmission line integrated therewith; a power divider for receiving an input signal and dividing the input signal into a plurality of divided signals; a plurality of time delay paths, each of the time delay paths coupled to an output of the power divider to receive at least one of the divided signals, wherein at least one of the time delay paths is in signal communication with the at least one transmission line to define a time delay associated therewith; a phase shifter circuit in signal communication with at least one of the time delay paths for controlling a phase of at least one of the divided signals, independent of the time delay associated therewith; and an amplitude control circuit in signal communication with at least one of the time delay paths for controlling an amplitude of at least one of the divided signals, independent of the time delay associated therewith; and a power combiner for receiving the divided signals and combining the signals into an output signal.

In yet another embodiment, a signal conditioning device comprises: a substrate including at least one transmission line integrated therewith; and a die mounted on the substrate, the die including a signal conditioning circuit having: a power divider for receiving an input signal and dividing the input signal into a plurality of divided signals; a plurality of time delay paths, each of the time delay paths coupled to an output of the power divider to receive at least one of the divided signals, wherein at least one of the time delay paths is in signal communication with the at least one transmission line to define a time delay associated therewith; a plurality of control devices for controlling at least one of a phase shift and an amplitude of at least one of the divided signals, wherein at least one of the control devices is disposed along each of the time delay paths and in signal communication therewith; and a power combiner for receiving the divided signals and combining the signals into an output signal.

FIGS. 1-2illustrate a signal conditioning device10(also referred to as a time amplitude phase control device or TAP device10) for providing selective, independent, and variable control over a time delay, an amplitude, and a phase of a radio frequency signal, according to an embodiment of the present invention. As shown, the TAP device10is implemented as a packaged radio frequency integrated circuit (RFIC) having a die12mounted to a substrate14and enclosed in a package16. As a non-limiting example, the substrate14is a multi-layer circuit board including a plurality of striplines17or conductive transmission lines integrated therewith to provide pre-determined time delays. As a non-limiting example, the striplines17are embedded within the substrate14. It is understood that any number of the striplines17can be used. It is further understood that any substrate material can be used. In certain embodiments, the striplines17are integrated into the package16and the die12is mounted directly thereto, wherein the package16operates as a substrate. Any substrate and packaging technique can be used. For example, the TAP device10may be packaged using a liquid crystal polymer package, a quad fiat no lead (QFN) package, or any other surface mount technology, now known or later developed.

As more clearly shown inFIG. 2, the TAP device10includes a power supply18, a control logic20, and a signal conditioning circuit22. In certain embodiments, at least one of the power supply18and the control logic20is integrated with the die12. However, other configurations can be used.

The power supply18is typically a direct current (DC) power supply. However, any source of electrical energy can be used.

The control logic20includes circuits for selectively activating and adjusting the various components of the TAP device10. It is understood that the control logic20may be used for any of a variety of other suitable functions for the TAP device10. It is further understood that the control logic20may include any number of hardware and software components to route and process signals and control the functionality of the signal conditioning circuit22.

The signal conditioning circuit22is typically disposed on the die12or embedded therein. However, other configurations can be used. The signal conditioning circuit22includes an input24to receive a signal (e.g. radio frequency signal) and direct the signal to a two-way power divider26. As a non-limiting example, the power divider26is an in-phase power divider such as a MA/COM DS-327. However, other power dividers can be used such as a Wilkinson power divider, for example. The outputs of the power divider26are coupled to a first time delay path28and a second time delay path30, respectively. It is understood that a length of each of the time delay paths28, is selectively varied by coupling the delay paths28,30to one of the striplines17embedded in the substrate14or package16, thereby independently varying a time delay associated with a signal transmitted therethrough.

A plurality of control devices, namely a phase shifter32and a variable gain amplifier34, are disposed along each of the delay paths28,30to provide selective, variable, and independent control over a phase and amplitude of the signals transmitted therethrough. As a non-limiting example, the phase shifters32and the variable gain amplifiers34are controlled in accordance with the methods disclosed in commonly owned U.S. Pat. No. 7,009,560, hereby incorporated herein by reference in its entirety. The signals transmitted through the delay paths28,30are directed to a two-way power combiner36. Another of the phase shifter32and the variable gain amplifier34are in signal communication with an output of the power combiner36to provide phase and amplitude control over a signal transmitted to the output38of the TAP device10. In certain embodiments, the control devices32,34disposed at the output38are different than the phase shifter32and the amplifier34disposed along the time delay paths28,30.

It is understood that any number of control devices can be used to adjust a phase and amplitude of a signal transmitted through the TAP device10. It is further understood that any type of control device can be used to provide control over at least one of the phase and amplitude of a signal transmitted through the TAP device10such as a variable attenuator and an I and Q vector modification circuit, for example.

FIG. 3illustrates the signal conditioning circuit22having a first time delay configuration. As shown, the first time delay path28has a length to produce a time delay of δminand the second time delay path30has a length to produce a time delay of t+δmin.

FIG. 4illustrates the signal condition circuit22having a second time delay configuration. As shown, the first time delay path28has a length to produce a time delay of t+δminand the second time delay path30has a length to produce a time delay of 2 t+δmin.

In use, the power divider26receives a signal from the input24of the TAP device10and generates a plurality of divided signals. Each of the divided signals is routed through at least one of the time delay paths28,30for signal conditioning. A time delay of each of the divided signals is determined by a length of an associated one of the time delay paths28,30. It is understood that any of the divided signals can be routed through any of the striplines17disposed in the substrate14or package16. The phase shifter32and amplifier34(i.e. control devices) selectively and independently control a phase and amplitude of the divided signal transmitted through an associated one of the time delay paths28,30. As a non-limiting example the control logic20controls the functionality of at least one of the phase shifter32and the amplifier34. The divided signals are combined by the power combiner36to form an output signal that is transmitted through the output38. A phase and an amplitude of the output signal can be adjusted by the phase shifter32and the amplifier34disposed between the output38and the power combiner36.

FIG. 5illustrates a tap device100according to another embodiment of the present invention similar to the tap device10except as described herein below. Specifically, a signal condition circuit102of the tap device100includes an input104to receive a signal (e.g. radio frequency signal) and direct the signal to a three-way power divider106. The outputs of the power divider106are coupled to a first time delay path108, a second time delay path110, and a third time delay path112, respectively. It is understood that a length of each of the time delay paths108,110,112is selectively varied by coupling the delay paths108,110,112to one of a plurality of striplines113thereby independently varying a time delay associated with a signal transmitted therethrough. A plurality of control devices, namely a phase shifter114and a variable gain amplifier116, are disposed along each of the delay paths108,110,112to provide selective, variable, and independent phase and amplitude control over the signals transmitted therethrough. As a non-limiting example, the phase shifters114and the variable gain amplifiers116are controlled in accordance with the methods disclosed in commonly owned U.S. Pat. No. 7,009,560. The signals transmitted through the delay paths108,110,112are directed to a three-way power combiner118. Another phase shifter114and variable gain amplifier116are in signal communication with an output of the power combiner118to provide phase and amplitude control over a signal transmitted to the output120. In certain embodiments, the control devices114,116disposed at the output120are different than the phase shifter114and the amplifier116disposed along the time delay paths108,110,112. It is understood that any number of control devices114,116can be used to adjust a phase and amplitude of a signal transmitted through the TAP device100. It is further understood that any type of control device can be used to provide control over at least one of the phase and amplitude of a signal transmitted through the TAP device100such as a variable attenuator and an I and Q vector modification circuit, for example.

FIG. 6illustrates a tap device200according to another embodiment of the present invention similar to the tap device100except as described herein below. Specifically, a signal condition circuit202of the tap device200includes an input204to receive a signal (e.g. radio frequency signal) and direct the signal to a three-way power divider206. The outputs of the power divider206are coupled to a first time delay path208, a second time delay path210, and a third time delay path212, respectively. It is understood that a length of each of the time delay paths208,210,212is selectively varied by coupling the delay paths208,210,212to one of a plurality of striplines (not shown), thereby independently varying a time delay associated with a signal transmitted therethrough. An amplitude/phase control device (APC)214is disposed along each of the delay paths208,210,212to provide selective, variable, and independent control over at least one of a phase and an amplitude of the signals transmitted therethrough. As a non-limiting example, the APC's214are similar to the control device described in U.S. Pat. No. 6,016,304, hereby incorporated herein by reference in its entirety. However, it is understood that other devices for controlling at least one of a phase and an amplitude of a signal can be used such as variable phase shifters, variable gain amplifiers, and I and Q signal processing devices or systems. The signals transmitted through the delay paths208,210,212are directed to a three-way power combiner216. Another APC214is in signal communication with an output of the power combiner216to provide phase and amplitude control over a signal transmitted to an output218. In certain embodiments, the control device214disposed at the output218is different than the APC214disposed along the time delay paths208,210,212. It is understood that any number of control devices214can be used to adjust a phase and amplitude of a signal transmitted through the TAP device200. It is further understood that any type of control device can be used to provide control over at least one of the phase and amplitude of a signal transmitted through the TAP device200such as a variable attenuator and an I and Q vector modification circuit, for example.

In the embodiment shown inFIG. 6, the first time delay path208has a length to produce a time delay of δmin, the second time delay path210has a length to produce a time delay of 2 t+δmin, and the third time delay path212has a length to produce a time delay of t+δmin. It is understood that any the paths208,210,212can have any length to provide any time delay.

FIG. 7illustrates a TAP device200′ according to another embodiment of the present invention similar to the TAP device200ofFIG. 6except as described below. Structure repeated from the description ofFIG. 6includes the same reference numeral and a prime (′) symbol. As shown, a signal condition circuit202′ includes a power divider220coupled to an output218′ to divide the output signal into a plurality of divided output signals. As a non-limiting example the power divider220is a two-way power divider having a pair of divided outputs221. However, any number of divided outputs can be used.

FIG. 8illustrates a TAP device200″ according to another embodiment of the present invention similar to the TAP device200ofFIG. 6except as described below. Structure repeated from the description ofFIG. 6includes the same reference numeral and a double-prime (″) symbol. As shown, a signal condition circuit202″ includes a power combiner222coupled to an input204″ to combine a plurality of received signals into a single input signal to be transmitted through the input204″ for conditioning. As a non-limiting example the power combiner222is a two-way power combiner having a pair of divided inputs223, each of the divided inputs223capable of receiving a signal (e.g. RF signal). However, any number of divided inputs can be used.

FIG. 9illustrates a TAP device200″ according to another embodiment of the present invention similar to the TAP device200ofFIG. 6except as described below. Structure repeated from the description ofFIG. 6includes the same reference numeral and a triple-prime (′″) symbol. As shown, a signal condition circuit202′″ includes a power divider224and a power combiner226. As a non-limiting example the power divider224is a two-way power divider having a pair of divided outputs225. However, any number of divided outputs can be used. The power divider224is coupled to an output218′″ to divide the output signal into a plurality of divided output signals. The two-way power combiner226is coupled to an input204′″ to combine a plurality of received signals into a single input signal to be transmitted through the input204′″ for conditioning. As a non-limiting example the power combiner226is a two-way power combiner having a pair of divided inputs227, each of the divided inputs227capable of receiving a signal (e.g. RF signal). However, any number of divided inputs can be used.

FIG. 10illustrates a plurality of the TAP devices10mounted on a circuit board300. It is understood that any number and combination of TAP devices10,100,200,200′,200″,200′″ can be electrically coupled to the circuit board300. The circuit board300includes a plurality of conductive transmission lines302disposed thereon or embedded therein. Each of the transmission lines302has a pre-determined length to provide a time delay to a signal transmitted therethrough. As a non-limiting example, any of the time delay paths28,30,108,110,112,208,210,212,208′,210′,212′,208″,210″,212″,208′″,210′″,212′″ of any of the TAP devices10,100,200,200′,200″,200″ can be electrically coupled to at least one of the transmission lines302and routed back to the associated signal condition circuit22,102,202,202′,202″,202′″ to provide a desired time delay.

FIG. 11illustrates the signal conditioning circuit202in electrical communication with a plurality of transmission lines302of the circuit board300. As a non-limiting example, a signal can be routed through any number of the transmission lines by at least one of a plurality of switches304. It is further understood the switches304can be used to bypass the transmission lines302so that no time delay is introduced to a signal prior to the input24,104,204of the respective TAP device10,100,200,200,200′,200″,200′″. In particular, one of the switches304routes an incoming signal through one of the transmission lines302having a discrete time delay step of 4t and another one of the switches304routes the incoming signal through one of the transmission lines302having a discrete time delay step of 2t.

The TAP device10,100,200,200,200′,200″,200′″ of the present invention is implemented using RFIC technology to minimize an overall package size and provide a lower power consumption, a lower cost, and a simplicity of use. The TAP device10,100,200,200,200′,200″,200′″ provides selective, independent, and variable control over a time delay, amplitude, and phase of a radio frequency signal. Specifically, the invention provides a time delay while substantially maintaining a phase of the carrier constant.

From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, make various changes and modifications to the invention to adapt it to various usages and conditions.