Apparatus and methods for front-end systems with directional couplers and a shared back switch are provided. In certain configurations, a method includes transmitting a first transmit signal from a first transmit port to an antenna port, generating a first coupled signal in response to the first transmit signal using a first directional coupler, providing the first coupled signal to a receive port by way of a first loopback selection switch and a shared back switch, transmitting a second transmit signal from a second transmit port to the antenna port, generating a second coupled signal in response to the second transmit signal using a second directional coupler, and providing the second coupled signal to the receive port by way of a second loopback selection switch and the shared back switch.

A radio frequency circuit includes a substrate, a first terminal disposed on a first principal surface of the substrate, a second terminal disposed on the first principal surface, a first-surface mounted component disposed on the first principal surface or inside the substrate, and a second-surface mounted component disposed on a second principal surface of the substrate which is opposite the first principal surface. A radio-frequency signal, which is input to the first terminal, is transmitted, for output from the second terminal, so as to make at least one round trip between the first principal surface and the second-surface mounted component, which is disposed on the second principal surface, through wiring lines disposed in the substrate.

Various embodiments disclosed herein enable steerable, time division duplex (“TDD”) communications channels at millimeter-wave frequency bands. Among other things, embodiments disclosed herein provide improved steering accuracy and power distribution, lower power consumption, and potentially longer service life than previous transceiver systems.

Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a method of coexistence management includes generating an RF observation signal based on observing a cellular transmit signal using a cellular front end system, processing the RF observation signal to generate digital observation data using a cellular transceiver, generating a digital wireless local area network receive signal based on processing an RF wireless local area network receive signal using a wireless local area network transceiver, processing the digital observation data to determine an estimated amount of aggressor spectral regrowth present in the RF wireless local area network receive signal using a spectral regrowth modeling circuit of the wireless local area network transceiver, and compensating the digital baseband wireless local area network receive signal for RF signal leakage based on the estimated amount of aggressor spectral regrowth.

A transceiver includes a radio-frequency (RF) front-end circuit, a dedicated RF front-end circuit, and a switchable matching circuit. The RF front-end circuit deals with communications of at least a first wireless communication standard. The dedicated RF front-end circuit deals with communications of a second wireless communication standard only. The switchable matching circuit is coupled to the RF front-end circuit, the dedicated RF front-end circuit, and a signal port of a chip. The switchable matching circuit provides impedance matching between the signal port and the RF front-end circuit when the RF front-end circuit is in operation, and provides impedance matching between the signal port and the dedicated RF front-end circuit when the dedicated RF front-end circuit is in operation. The RF front-end circuit, the dedicated RF front-end circuit, and the switchable matching circuit are integrated in the chip.

A radio frequency (RF) system is provided. The RF system includes an RF transceiver, an RF processing circuit, a transfer switch module, a first antenna, a second antenna, a third antenna, and a fourth antenna. The RF transceiver is coupled with the RF processing circuit. The RF processing circuit is coupled with the transfer switch module. The transfer switch module is coupled with the first antenna, the second antenna, the third antenna, and the fourth antenna. When the RF system operates in a non-standalone (NSA) mode, the first antenna is configured for transmission in a first low band (LB) and primary reception in the first LB, the second antenna is configured for transmission in a second LB and primary reception in the second LB, the third antenna is configured for diversity reception in the second LB, and the fourth antenna is configured for diversity reception in the first LB.

An electronic device including a housing, at least one antenna disposed inside the housing or disposed on at least a part of the housing, a first transceiver configured to generate a first signal corresponding to a first communication network and transmit the first signal to the at least one antenna, a second transceiver configured to generate a second signal corresponding to a second communication network and transmit the second signal to the at least one antenna, a first coupler electrically connected between the at least one antenna and the first transceiver, a first communication processor operatively connected to the first transceiver, and a second communication processor operatively connected to the second transceiver, wherein the second communication processor is configured to control a transmission power of the second signal, at least partially based on a signal received via feedback by the first coupler.

Radio frequency (RF) communication systems with coexistence management are provided herein. In certain embodiments, a mobile device includes a first antenna, a first front end system that receives an RF receive signal from the first antenna, a first transceiver coupled to the first front end system, a second antenna, a second front end system that provides an RF transmit signal to the second antenna, and a second transceiver coupled to the second front end system. The second front end system observes the RF transmit signal to generate an RF observation signal, which is downconverted and processed by the second transceiver to generate digital observation data that is provided to the first transceiver. The first transceiver downconverts the RF receive signal to baseband, and compensates the baseband receive signal for an amount of RF signal leakage indicated by the digital observation data.

To control antenna characteristics in an electronic device, a method for operating the electronic device may include identifying communication states related to a first radio access technology (RAT) and a second RAT, determining a mode of a tuner which controls characteristics of an antenna for the second RAT, based on the communication states, and controlling the tuner according to the mode.

An RF system and an electronic device are provided. The RF system includes an RF transceiver, an RF processing circuit coupled with the RF transceiver, a transfer switch module, a first antenna, a second antenna, a third antenna, and a fourth antenna. The RF processing circuit includes a first Tx module, a second Tx module, a third Tx module, a combiner, a directional coupler, a first Rx module, a second Rx module, a third Rx module, a fourth Rx module, a hexaplexer, a first duplexer module, a second duplexer module, a first filter, a second filter, a first selector-switch, a second selector-switch, and a third selector-switch. The RF system and the electronic device can adopt four antennas to support LB+LB NSA and MHB+MHB NSA simultaneously, so as to greatly improve versatility of NSA on the electronic device.