A front-end module is provided. The front-end module includes a reception amplifier configured to amplify a received radio-frequency (RF) signal, first and second series switches configured to control a switching operation to electrically connect an output terminal of the reception amplifier and first and second reception ports to each other, a radio-frequency (RF) splitter configured to simultaneously transfer a received RF signal, amplified by the reception amplifier or bypassing the reception amplifier, to the first and second reception ports, first and second shunt switches configured to control a switching operation to electrically connect a ground and first and second branch nodes between the RF splitter and the first and second reception ports to each other, and first and second reflected wave removing impedance elements electrically connected between the first and second branch nodes and a ground.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit under 35 USC 119(a) of Korean Patent Application No. 10-2020-0044726 filed on Apr. 13, 2020 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes.

BACKGROUND

The following description relates to a front-end module.

2. Description of Related Art

To increase the communications speed of wireless local area networks (WLAN), communications technology having a wide bandwidth and a high throughput rate and communications protocol standardization are continuously performed. Standardization of Wi-Fi6 (802.11ax), a next-generation standard, to which technologies such as Orthogonal frequency-division multiple access (OFDMA), multi user-multiple input multiple output (MU-MIMO), and the like, for high-density/high-efficiency WLAN are applied, is currently being implemented to achieve not only an increase in communications speed, but also further improved communications performance in indoor and outdoor environments in which access points (AP) and mobile terminals are crowded. In 2018, the US Federal Communications Commission (FCC) has additionally allocated the 6 GHz band (5.925 to 7.125 GHz) for unlicensed use, so that a bandwidth of 1200 MHz could be secured to support higher communication speeds and to provide various Wi-Fi 6 services.

Additionally, Long Term Evolution (LTE) licensed assisted access (LTE-LAA) carrier aggregation (CA) is in the spotlight for the implementation of smooth service as 5G mobile communication services have been commercialized based on high-speed data transfer. LTE-LAA CA is a technology in which an LTE licensed band and an unlicensed band, including a Wi-Fi frequency, may be combined to transfer data in a wider band. Existing CA technology may successfully implement a higher communications speed, but the higher communications speed did not satisfy a communications speed necessary for 5G mobile communications.

Accordingly, an LTE frequency band of 20 MHz and a Wi-Fi frequency band of 60 MHz, an unlicensed band, were combined to achieve a transfer rate about 10 times higher than a transfer rate of existing LTE, which satisfied the communications speed necessary for 5G mobile communications. Similarly, transmitting and receiving ends of a mobile device, in which LTE-LAA and Wi-Fi wireless environments coexist while satisfying the next-generation Wi-Fi standard, should be provided with a front-end module, having wide band characteristics, that performs a co-existence operation and covers a band of 60 GHz. Additionally, since a low-noise amplifier (LNA) disposed on a reception path may play an important role to affect overall performance of a receiver, low-noise characteristics, a high voltage gain, and linear characteristics may be beneficial.

SUMMARY

In a general aspect, a front-end module includes a reception amplifier configured to amplify a received radio-frequency (RF) signal; a first series switch configured to control a switching operation to electrically connect an output terminal of the reception amplifier and a first reception port to each other; a second series switch configured to control a switching operation to electrically connect the output terminal of the reception amplifier and a second reception port to each other; a radio-frequency (RF) splitter configured to simultaneously transfer one of a received RF signal that is amplified by the reception amplifier, and a received RF signal that bypasses the reception amplifier, to the first reception port and the second reception port; a first shunt switch configured to control a switching operation to electrically connect a ground and a first branch node between the RF splitter and the first reception port to each other; a second shunt switch configured to control a switching operation to electrically connect the ground and a second branch node between the RF splitter and the second reception port; a first reflected wave removing impedance element electrically connected between the first branch node and the ground; and a second reflected wave removing impedance element electrically connected between the second branch node and the ground.

The front-end module may include a controller configured to operate in a selected mode, among a first mode, a second mode, and a third mode, to control the first series switch and the second series switch, and control the first shunt switch and the second shunt switch, wherein the controller, when configured to operate in the first mode, controls the first series switch and the second shunt switch in an ON state, and controls the second series switch and the first shunt switch in an OFF state, the controller, when configured to operate in the second mode, controls the second series switch and the first shunt switch in an ON state, and controls the first series switch and the second shunt switch in an OFF state, and the controller, when configured to operate in the third mode, controls the first series switch and the second series switch in an ON state, and controls the first shunt switch and the second shunt switch in an OFF state.

The RF splitter may be configured to transfer a received RF signal of a first communications protocol to the first reception port when the controller operates in the first mode, and transfer a received RF signal of a second communications protocol, different from the first communications protocol, when the controller operates in the second mode, and at least a portion of a frequency band of the first communications protocol and at least a portion of a frequency band of the second communications protocol overlap each other.

The front-end module may include a transceiving branch switch electrically connected between an input terminal of the reception amplifier and an antenna port; a third series switch configured to control a switching operation to electrically connect the transceiving branch switch and the first reception port to each other; and a third shunt switch configured to control a switching operation to electrically connect a ground and a node between the transceiving branch switch and the first reception port to each other; wherein the transceiving branch switch is configured to transfer a received RF signal from the antenna port to one of the first reception port and the second reception port through the RF splitter when the transceiving branch switch operates in a receiving mode, and transfer a transmitted RF signal from the first reception port to the antenna port by bypassing the RF splitter when the transceiving branch switch operates in a transmitting mode.

The front-end module may include a transmission amplifier input port configured to be electrically connected to the third series switch, and to be electrically connected to an input terminal of an external transmission amplifier; and a transmission amplifier output port configured to be electrically connected to the transceiving branch switch and to be electrically connected to an output terminal of the transmission amplifier.

The first series switch may be configured to control a switching operation to electrically connect the first branch node and the first reception port to each other, and the second series switch may be configured to control a switching operation to electrically connect the second branch node and the second reception port to each other.

The first reflected wave removing impedance element may be connected in series between the first branch node and the ground, and has a matched resistance value such that a reflected wave of a received RF signal passes from the first branch node to a ground, and the second reflected wave removing impedance element may be connected in series between the second branch node and the ground, and has a matched resistance value such that a reflected wave of a received RF signal passes from the second branch node to a ground.

The first reflected wave removing impedance element may include a first reflected wave removing resistor and a first switch capacitor that are connected in series with each other, and the second reflected wave removing impedance element may include a second reflected wave removing resistor and a second switch capacitor that are connected in series with each other.

The RF splitter may include a first inductor electrically connected in series between an output terminal of the reception amplifier and the first branch node; a second inductor electrically connected in series between an output terminal of the reception amplifier and the second branch node; and a resistor electrically connected between a second end of the first inductor and a second end of the second inductor.

The RF splitter may include a first capacitor electrically connected between a first end of the first inductor and a ground; and a second capacitor electrically connected between a first end of the second inductor and the ground.

The RF splitter may include a first capacitor electrically connected between a first end of the first inductor and the ground; a second capacitor electrically connected between a first end of the second inductor and the ground; a third capacitor electrically connected between a second end of the first inductor and the ground; and a fourth capacitor electrically connected between a second end of the second inductor and the ground.

The first capacitor, the second capacitor, the third capacitor, and the fourth capacitor, and the first inductor and the second inductor may have impedances such that a received RF signal of a fundamental frequency, belonging to a band of 5.1 GHz to 7.2 GHz, may be transferred to at least one of the first reception port and the second reception port.

The reception amplifier may include a first amplifier transistor and a second amplifier transistor combined in a cascode configuration; and an intermediate inductor electrically connected in series between the first amplifier transistor and second amplifier transistors.

The reception amplifier may include a shunt output inductor electrically connected in series between an output terminal of the first amplifier transistor and a power source; a series output capacitor electrically connected in series between the output terminal of the first amplifier transistor and the RF splitter; a shunt output capacitor electrically connected in series between the output terminal of the first amplifier transistor and the RF splitter, and a ground; and a series output inductor electrically connected in series between the output terminal of the first amplifier transistor and the RF splitter.

In a general aspect, a radio-frequency (RF) module includes a first reception port; a second reception port; an RF splitter; a transceiver, configured to receive an RF signal from an antenna port and transmit the received RF signal to one of the first reception port and the second reception port through the RF splitter in a receiving mode, and transfer a transmitted RF signal from the first reception port to the antenna port by bypassing the RF splitter when operating in a transmitting mode; and wherein the RF splitter may be configured to: transmit a first RF signal of the received RF signal to one of the first reception port and the second reception port in a first mode; transmit a second RF signal of the received RF signal to another of the first reception port and the second reception port in a second mode, and simultaneously transmit the first RF signal and the second RF signal to the first reception port and the second reception port in a third mode.

The first RF signal may be of a first communication protocol, and the second RF signal may be of a second communication protocol that is different from the first communication protocol.

DETAILED DESCRIPTION

FIG. 1Aillustrates a front-end module, in accordance with one or more embodiments.

Referring toFIG. 1A, a front-end module100aaccording to an example may include a reception amplifier110aand a radio-frequency (RF) splitter200a. In a non-limiting example, all circuits included in the front-end module100amay be configured as a single integrated circuit (IC), and the RF splitter200amay be embedded in the front-end module100a.

The reception amplifier110amay amplify a received radio-frequency (RF) signal. The received RF signal may be remotely received by an antenna electrically connected to an antenna port ANT, and the reception amplifier110amay amplify the received RF signal while suppressing an increase in noise due to amplification.

The received RF signal may be transferred to a first reception port RP1and/or a second reception port RP2through the RF splitter200ain a state in which the received RF signal is amplified by the reception amplifier110aor the received RF signal bypasses the reception amplifier110athrough a bypass path115a.

The RF splitter200amay be electrically connected between an output terminal of the reception amplifier110aand the first and second reception ports RP1and RP2, and may selectively transfer the received RF signal to selective ones of the first and second reception ports RP1and RP2, or may simultaneously transfer the received RF signal to the first and second reception ports RP1and RP2.

For example, the received RF signal may simultaneously include a first RF signal of a first communication standard (for example, Wi-Fi) and a second RF signal of a second communication standard (as a non-limited example, LTE Licensed Assisted Access (LTE-LAA)). The first and second RF signals may be simultaneously transmitted to both the first and second reception ports RP1and RP2.

Accordingly, a first communication modem electrically connected to the first reception port RP1, and a second communication modem electrically connected to the second reception port RP2may process the first and second RF signals at a speed two or more times higher than in a time division duplexing (TDD) manner to obtain received information.

The RF splitter200amay have a first transmission impedance between an output terminal of the reception amplifier110aand the first reception port RP1and a second transmission impedance between an output terminal of the reception amplifier110aand the second reception port RP2. When the respective first and second transmission impedances match impedances corresponding to frequencies of the respective first and second RF signals of respective different communication standards included in the received RF signal, the respective first and second RF signals may be simultaneously transferred to the first and second reception ports RP1and RP2.

For example, the RF splitter200amay simultaneously transfer the respective first and second RF signals, included in the received RF signal, to both the first and second reception ports RP1and RP2using only passive elements.

A first communication of a first communications protocol, and a second communication of a second communications protocol may be individually performed depending on an environment or implementation of each of the first and second communications, or an environment or implementation of an electronic device in which the front-end module100ais disposed.

The first and second communication modems may be temporarily switched to operate in a manner, in which the first and second communications are individually performed, such as, for example, a TDD manner. In this example, the first RF signal, transferred to the second communication modem when the first communication modem receives the first RF signal, may deteriorate reception sensitivity of the second RF signal of the second communication modem or performance of the front-end module100a, and the second RF signal, transferred to the first communication modem when the second communication modem receives the second RF signal, may deteriorate reception sensitivity of the first RF signal of the first communication modem or the performance of the front-end module100a.

Therefore, the front-end module100amay simultaneously transfer the first and second RF signals, included in the received RF signal, to both the first and second reception ports RP1and RP2. The front-end module100amay also selectively transfer the first and second RF signals, included in the received RF signal, to a corresponding one of the first and second reception ports RP1and RP2.

Referring toFIG. 1A, the front-end module100amay include a first branch switch11a-1, a second branch switch12a, a first reflected wave removing impedance element241, and a second reflected wave removing impedance element242.

The first branch switch11a-1may include a first series switch and a first shunt switch, and may operate and select one of a path between the RF splitter200aand the first reception port RP1, and a path between the RF splitter200aand the first reflected wave removing impedance element241.

The second branch switch12amay include a second series switch and a second shunt switch, and may operate to select one of a path between the RF splitter200aand the second reception port RP2, and a path between the RF splitter200aand the second reflected wave removing impedance element242.

When the first branch switch11a-1electrically connects the RF splitter200aand the first reception port RP1to each other, and the second branch switch12aseparates the RF splitter200aand the second reception port RP2, the received RF signal may not be transferred to the second reception port RP2.

In an example, the RF splitter200amay simultaneously transfer the received RF signal to the first and second reception ports RP1and RP2, irrespective of the operation of the first and second branch switches11a-1and12a.

When the second branch switch12aonly separates the RF splitter200aand the second reception port RP2, among elements of the received RF signal, an element transferred to the second reception port RP2may be reflected on the second branch switch12a. A reflected wave of the received RF signal may be transferred to the reception amplifier110a, and may deteriorate performance of the reception amplifier110aand may deteriorate the overall performance of the front-end module100athrough the RF splitter200a.

The second branch switch12aof the front-end module100amay electrically connect the second reflected wave removing impedance element242to the RF splitter200a, while separating the RF splitter200aand the second reception port (RP2) from each other. Accordingly, the second reflected wave removing impedance element242may remove an element received RF signal transferred to the second reception port RP2, among elements of the received RF signal, and may prevent performance degradation of the reception amplifier110aand prevent overall performance degradation of the front-end module100a.

The second branch switch12amay electrically connect the RF splitter200aand the second reception port RP2to each other, and the received RF signal may not be transferred to the first reception port RP1when the first branch switch11a-1separates the RF splitter200aand the first reception port RP1from each other.

In an example, the RF splitter200amay simultaneously transfer the received RF signal to the first and second reception ports RP1and RP2, irrespective of operations of the first and second branch switches11a-1and12a.

When the first branch switch11a-1only separates the RF splitter200aand the first reception port RP1from each other, among elements of the RF signal, an element transferred to the first reception port RP1may be reflected on the first branch switch11a-1. A reflected wave of the received RF signal may be transferred to the reception amplifier110ato deteriorate performance of the reception amplifier110a, and may cause deterioration in overall performance of the front-end module100athrough the RF splitter200a.

The first branch switch11a-1of the front-end module100amay electrically connect the first reflected wave removing impedance element241to the RF splitter200awhile separating the RF splitter200aand the first reception port RP1from each other. Accordingly, the first reflected wave removing impedance element241may remove the element transferred to the first reception port RP1, among elements of the received RF signal, and may prevent deterioration in overall performance of the reception amplifier110aand front-end module100a.

The controller120may control the first and second branch switches11a-1and12a. When operating in a first mode, the controller120may operate such that the reception RF signal is transferred to only the first reception port RP1, rather than the second reception port RP2. When operating in a second mode, the controller120may operate such that the reception RF signal is transferred to only the second reception port RP2, rather than the first reception port RP1. When operating in a third mode, the controller may operate such that the reception RF signal is simultaneously transferred to both the first and second reception ports RP1and RP2.

In an example, the first branch switch11a-1and the second branch switch12amay include a semiconductor transistor, and the controller120may output a control voltage input to a gate terminal of the semiconductor transistor. The semiconductor transistor may electrically connect a drain terminal and a source terminal of the semiconductor transistor to each other when a control voltage is high, and may separate the drain terminal and the source terminal of the semiconductor transistor from each other when the control voltage is low.

For example, the controller120may receive mode control voltages VC0, VC1, VC2, and VC3, a bias voltage VBS, and power source VREF from an external device (for example, a communication modem or a PMIC) of the front-end module100aVREF, may control the first and second branch switches11a-1and12abased on mode control voltages VC0, VC1, VC2, and VC3, may use a bias voltage VBS and the power source VREF, and may provide the bias voltage VBS and the power source VREF to the reception amplifier110a.

For example, the front-end module100amay transfer a reception RF signal of a first communications protocol (for example, W-Fi) to the first reception port RP1when the controller120operates in the first mode, may transfer a reception RF signal of a second communications protocol (for example, LTE-LAA), different from the first communications protocol, when the controller120operates in the second mode, and may simultaneously transfer reception RF signals of the first and second communications protocols to the first and second reception ports RP1and RP2when the controller120operates in the third mode. In this example, at least a portion of a frequency band of the first communications protocol and at least a portion of a frequency band of the second communications protocol may overlap each other.

Referring toFIG. 1A, the front-end module100amay further include a transceiving branch switch132a-1electrically connected between an input terminal of the reception amplifier110aand the antenna port ANT.

The first branch switch11a-1may operate to select one of a path through the RF splitter200aand a path bypassing the RF splitter200a, among a plurality of paths between the first reception port RP1and the transceiving branch switch132a-1. In an example, the first branch switch11a-1may further include a third series switch and a third shunt switch.

In an example, the transceiving branch switch132a-1may be configured to transfer the received RF signal from the antenna port ANT to the first reception port RP1or the second reception port RP2through the RF splitter200awhen operating in the receiving mode, and to transfer the transmitted RF signal from the first reception port RP1to the antenna port ANT by bypassing the RF splitter200awhen operating in the transmitting mode. For example, the first reception port RP1may be used as a transmission path of a transmitted RF signal as well as the received RF signal.

Accordingly, a circuit electrically connected to the first reception port RP1may not only receive the received RF signal through the RF splitter200a, but may also transfer the RF signal to the antenna ANT or receive the RF signal from the antenna ANT by bypassing the RF splitter200a. When the RF signal is transferred by bypassing the RF splitter200a, the transceiving branch switch132a-1and the first branch switch11a-1may inhibit the reflected wave of the RF signal from being transferred to the RF splitter200a.

For example, the front-end module100amay include a transmission amplifier input port, configured to be electrically connected to a first branch switch11a-1and electrically connected to an input terminal of an external transmission amplifier90a, and a transmission amplifier output port configured to be electrically connected to the transceiving branch switch132a-1and electrically connected to an output terminal of the transmission amplifier90a.

In an example, the front-end module100amay provide the transmission path of the transferred RF signal, but may not include the transmission amplifier90a.

Since the transmission amplifier90aamplifies a relatively high power transmission RF signal, the transmission amplifier90amay be separated from the transmission amplifier110aand the radio-frequency splitter200aof the front-end module100ato be more advantageously implemented to enhance energy efficiency. Since a ratio of power consumption of the transmission amplifier90ais high relative to overall power consumption of the antenna to the communication modem, the transmission amplifier90amay be separated from the front-end module100ato reduce the overall power consumption of the antenna to the communication modem.

FIG. 1Billustrates a structure in which a transmitter is omitted in a front-end module, in accordance with one or more embodiments.

Referring toFIG. 1B, a front-end module100baccording to an example may include a first branch switch11a-2with a reduced branch path, and may include a transmitting/receiving branch switch132a-2with a reduced branch path. The transmitting/receiving branch switch132a-2may be configured such that a transmitted RF signal does not pass therethrough.

FIG. 2Ais a circuit diagram of a front-end module, in accordance with one or more embodiments.

Referring toFIG. 2A, a front-end module100caccording to an example may include a reception amplifier110band a radio-frequency (RF) splitter200b, and may include a first series switch221b, a second series switch222b, a first shunt switch223b, and a second shunt switch224b.

A combination of the first series switch221band the first shunt switch223bmay correspond to the first branch switch illustrated inFIGS. 1A and 1B, and a combination of the second series switch222band a second shunt switch224bmay correspond to the second branch switch illustrated inFIGS. 1A and 1B.

The first series switch221bmay be configured to control switching operations to electrically connect an output terminal of a reception amplifier110band a first reception port RP1to each other, and the second series switch222bmay be configured to control switching operations to electrically connect an output terminal of the reception amplifier110band the second reception port RP2to each other.

The first shunt switch223bmay be configured to control switching operations to electrically connect a ground and a first branch node BN1between the RF splitter200band the first reception port RP1to each other, and the second shunt switch224bmay be configured to control switching operations to electrically connect a ground and a second branch node BN2between the RF splitter200band the second reception port RP2to each other.

Each of the first and second series switches221band222band the first and second shunt switches223band224bmay control switching operations to electrically connect a drain terminal and a source terminal of a semiconductor transistor to each other, based on a voltage on a gate terminal, may have a structure in which a gate resistor is connected through a gate terminal, and may have a structure in which a drain resistor having a high resistance value is connected between a drain terminal and a source terminal. The drain resistor and/or the gate resistor may be omitted, and the semiconductor transistor may be implemented as a different type of transistor than a field effect transistor.

In an example, each of the first and second series switches211band212band the first, second, third, and fourth shunt switches221b,222b,223b, and224bmay be implemented as a silicon-on-insulator (SOI)-based DGNFET having improved frequency characteristics.

When the controller operates in a first mode, the first series switch221band the second shunt switch224bmay enter an ON state and the second series switch222band the first shunt switch223bmay enter an OFF state.

Accordingly, the first reception port RP1may be electrically connected to the RF splitter200b, and the second reflected wave removing impedance element242may be electrically connected to the RF splitter200b.

When the controller operates in a second mode, the second series switch222band the first shunt switch223bmay enter an ON state and the first series switch221band the second shunt switch224bmay enter an OFF state.

Accordingly, the second reception port RP2may be electrically connected to RF splitter200band the first reflected wave removing impedance element241may be electrically connected to the RF splitter200b.

When the controller operates in a third mode, the first and second series switches221band222bmay enter an ON state and the first and second shunt switches223band224bmay enter an OFF state.

Accordingly, the first and second reception ports RP1and RP2may be electrically connected to the RF splitter200band the received RF signal may be simultaneously transferred to the first and second reception ports RP1and RP2.

The first series switch221bmay be disposed to be closer to the first reception port RP1than the first shunt switch223bto control switching operations to electrically connect the first branch node BN1and the first reception port RP1to each other, and the second series switch222bmay be disposed to be closer to the second reception port RP2than the second shunt switch224bto control switching operations to electrically connect the second branch node BN2and the second reception port RP2to each other.

The first reflected wave removing impedance element241may be connected in series between the first branch node BN1and a ground, and may have a matched resistance value (for example, 50 ohms) such that the reflected wave of the received RF signal passes from the first branch node BN1to the ground, and the second reflected wave removing impedance element242may be connected in series between the second branch node BN2and a ground and may have a matched resistance value (for example, 50 ohms) such that the reflected wave of the received RF signal passes from the second branch node BN2to the ground. Accordingly, the reflected wave of the received RF signal may be transferred to the ground through the first or second reflected wave removing element241or242to be removed.

The first reflected wave removing impedance element241may include a first reflected wave removing resistor and a first switch capacitor243connected in series with each other, and a second reflected wave removing impedance element242may include a second reflected wave removing resistor and a second switch capacitor244connected in series with each other. Accordingly, the first and second switch capacitors243and244may contribute to a resonant frequency of the RF splitter200bto widen a bandwidth of the first and second switch capacitors243and244.

Referring toFIG. 2A, a front-end module100caccording to an example may further include at least one of a third series switch225b, a third shunt switch226b, and a third switch capacitor245.

A combination of the first and third series switches221band225band the first and third shunt switches223band226bmay correspond to the first branch switch illustrated inFIG. 1A.

Referring toFIG. 2A, a front-end module100cmay include at least one of a bypass path115b, transceiving branch switches132b-1,132b-2, and132b-3, and a matching terminal141of a first reception port, a matching terminal142of a second reception port, and a matching terminal143of an antenna port.

The transceiving branch switch132b-2may include a series switch132b-10, a shunt switch132b-11, and a capacitor132b-12, and the transmission amplifier90bmay include a power amplifier91, a capacitor92, and an inductor93.

The reception amplifier110bmay be supplied with power source VREG, and the bypass path115bmay be supplied with power source VDD.

FIG. 2Bis a circuit diagram illustrating a structure in which a transmitter is omitted in a front-end module in accordance with one or more embodiments.

Referring toFIG. 2B, a radio-frequency (RF) splitter200bof a front-end module100daccording to an example may include at least a portion of a first inductor231, a second inductor232, a first capacitor251, a second capacitor252, a third capacitor253, a fourth capacitor254, and a resistor255.

The first inductor231may be electrically connected in series between a common branch node and a first branch node, the second inductor232may be electrically connected in series between the common branch node and a second branch node, the resistor255may be electrically connected in series between the first and second branch nodes.

In an example, the first and second inductors231and232and the resistor255may be passive elements. A combination of the first inductor231and the resistor255may constitute at least a portion of a first transmission impedance between an output terminal of a reception amplifier110aand the first reception port RP1, and a combination of the second inductor232and resistors240amay constitute at least a portion of a second transmission impedance between the output terminal of the reception amplifier110aand a second reception port RP2. When the first and second transmission impedances match impedances corresponding to the frequencies of the first and second RF signals included in the received RF signal, the first and second RF signals may be simultaneously transferred to both the first and second reception ports RP1and RP2.

The first capacitor251may be electrically connected between the other end of the first inductor231and a ground, the second capacitor252may be connected between the other end of the second inductor232and a ground, the third capacitor253may be electrically connected between one end of the first inductor231and a ground, and the fourth capacitor254may be electrically connected between one end of the second inductor232and a ground.

Capacitances of the first, second, third, and fourth capacitors251,252,253, and254and inductances of the first and second inductors231and232may provide a resonant frequency of the RF splitter200b, and the RF splitter200bmay have a wider bandwidth based on the provided resonant frequency.

For example, the first, second, third, and fourth capacitors251,252,253, and254and the first and second inductors231,232may have impedances such that an RF signal of a fundamental frequency, belonging to a band of 5.1 GHz to 7.2 GHz, is transferred to at least one of the first and second reception ports RP1and RP2. Accordingly, the front-end module100dmay have a wide bandwidth stably covering a frequency band corresponding to W-Fi and a frequency band corresponding to LTE-LAA.

Referring toFIG. 2B, the second branch switch may include series switches132b-4,132b-7, and132b-13, shunt switches132b-5,132b-8, and132b-14, and capacitors132b-6,132b-9, and132b-15.

A bypass path may include a series switch115b-3and resistors115b-1and115b-2.

FIG. 2Cis a circuit diagram illustrating a structure in which a bypass circuit of a reception amplifier is omitted in a front-end module, in accordance with one or more embodiments.

Referring toFIG. 2C, a reception amplifier110bof a front-end module100eaccording to an example may include at least a portion of a first amplifier transistor111-1, a second amplifier transistor111-2, a third amplifier transistor111-3, a feedback transistor111-4, a shunt output inductor112-1, a series output capacitor113-1, a shunt output capacitor113-2, a series output inductor112-2, an intermediate inductor112-3, a source inductor112-4, an input inductor112-6, gate capacitors113-3,113-4, and113-5, an input capacitor113-6, gate resistors114-1,114-2,114-3, and114-5, and a back-to-back diode116.

Among the first, second, and third amplifier transistors111-1,111-2, and111-3, at least two amplifier transistors may be combined in a cascode structure. Accordingly, a gain of the reception amplifier110bmay be further increased, and frequency characteristics of the reception amplifier110bmay be further improved.

The intermediate inductor112-3may be electrically connected in series between two amplifier transistors, among the first, second, and third amplifier transistors111-1,111-2, and111-3. Accordingly, since the intermediate inductor112-3may cancel parasitic capacitances of the first, second, and third amplifier transistors111-1,111-2, and111-3, the intermediate inductor112-3may further increase the gain of the reception amplifier110band may further widen a bandwidth of the reception amplifier110b.

The shunt output inductor112-1may be electrically connected in series between an output terminal of the first amplifier transistor111-1and power source VREG, the series output capacitor113-1may be electrically connected in series between an output terminal of the first amplifier transistor111-1and the RF splitter200b, the shunt output capacitor113-2may be electrically connected in series between the output terminal of the first amplifier transistor111-1and the RF splitter200b, and a ground output, and the series output inductor112-2may be electrically connected in series between the output terminal of the first amplifier transistor111-1and the RF splitter200b.

Accordingly, the reception amplifier110bmay have a wider bandwidth based on a resonant frequency of the output impedance.

The input inductor112-6and the input capacitor113-6may include a notch filter, and may have a resonant frequency corresponding to a frequency of a second or third harmonic wave of the received RF signal (for example, 2.4 GHz). Accordingly, the input inductor112-6and the input capacitor113-6may remove the harmonic wave of the received RF signal generated by amplification of the reception amplifier110b.

The back-to-back diode116may stably provide an electrostatic discharge path of the reception amplifier110b.

A matching terminal of the first reception port RP1may include a series capacitor141-1and a shunt inductor141-2, a matching terminal of the second reception port RP2may include a series capacitor142-1and a shunt inductor142-2, a matching terminal of the antenna port ANT may include a series capacitor143-1and a shunt inductor143-2.

Accordingly, since the matching terminal may remove the harmonic wave of the received RF signal generated by amplification of the reception amplifier110band may reduce overall parasitic reactance of the front-end module100e, insertion loss at a relatively high frequency band (for example, 6 GHz) may be reduced, an overall frequency band of the front-end module100emay be easily increased, and an overall electrostatic discharge path of the front-end module100emay be stably secured.

FIG. 2Dis a circuit diagram illustrating a simplified structure of a reception amplifier and a simplified structure of a radio-frequency (RF) splitter in a front-end module, in accordance with one or more embodiments.

Referring toFIG. 2D, a reception amplifier110cof a front-end module100faccording to an example may have a structure simplified more than the structure of the reception amplifier illustrated inFIG. 2C, and a radio-frequency (RF) splitter200cmay have a structure simplified more than the structure of the reception amplifier illustrated inFIG. 2B.

FIG. 3illustrates a peripheral structure of a front-end module in accordance with one or more embodiments.

Referring toFIG. 3, a front-end module100aaccording to an example may be electrically connected to an antenna ANT1through an antenna port ANT, may be electrically connected to a first communication modem301through a first reception port RP1, and may be electrically connected to a second communication modem302through a second reception port RP2.

In an example, the front-end module100amay be electrically connected to a transmission amplifier through a transmission amplifier input port TXIN and a transmission amplifier output port TXOUT, and may receive mode control voltages VC0, VC1, VC2, and VC3from first and second communication modems301and302.

The front-end module100a, the first and second communication modems301and302, and the antenna ANT1may be disposed in an electronic device. The electronic device may be, as non-limiting examples, a smartphone, a personal digital assistant, a digital video camera, a digital still camera, a network system, a computer, a monitor, a tablet computer, a laptop computer, a netbook computer, a television, a video game console, a smartwatch, an automotive, or the like, but is not limited thereto.

An RF signal disclosed therein may have a form based on a protocol such as wireless fidelity (Wi-Fi) (Institute of Electrical And Electronics Engineers (IEEE) 802.11 family, or the like), worldwide interoperability for microwave access (WMAX) (IEEE 802.16 family, or the like), IEEE 802.20, long term evolution (LTE), evolution data only (Ev-DO), high speed packet access+ (HSPA+), high speed downlink packet access+ (HSDPA+), high speed uplink packet access+ (HSUPA+), enhanced data GSM environment (EDGE), global system for mobile communications (GSM), global positioning system (GPS), general packet radio service (GPRS), code division multiple access (CDMA), time division multiple access (TDMA), digital enhanced cordless telecommunications (DECT), Bluetooth, 3G, 4G, and 5G protocols, any other wireless and wired protocols designated after the abovementioned protocols, or the like, but the form of the RF signal is not limited thereto.

As described above, a front-end module according to an example may support effective and stable reception of a received RF signal in both a first case, in which first and second communication modems operate at the same time, and a second case in which first and second communication modems operate in a time division duplexing manner, and may prevent performance deterioration resulting from a reflected wave of the received RF signal.

In addition, a front-end module according to an example may have a higher frequency band and a wider bandwidth.