Abstract: Technologies directed to sharing an antenna and a frequency band between coexistence radios are described herein. In one device, semi-active front-end circuitry includes a directional coupler and a phase-shifter circuit coupled to two radios that use the same antenna and the same frequency band. The phase-shifter circuit and directional coupler create an isolation null at an isolated port of the directional coupler that cancels a copy of an incident wave of a transmit signal being applied at an input port of the directional coupler. The isolation null permits the second radio to receive a receive signal concurrently with the first radio transmitting the transmit signal.

Abstract: Antenna structures and methods of operating the same are described. One apparatus includes a processing device that executes an active interference cancellation (AIC) algorithm and radio frequency front-end (RFFE) circuitry coupled to the processing device. The RFFE circuitry includes two RF couplers, a fixed-delay filter, and an interference compensation circuit part of an electrical path between the two RF couplers. The AIC algorithm is operable to control the interference compensation circuit to adjust a phase, an amplitude or both of a copy of a first RF signal transmitted on a first antenna to remove corresponding interference in a second RF signal received at a second antenna that is caused by the first RF signal. The processing device triggers a re-calibration in the AIC algorithm when the digital values, received from a power detector circuit, indicate a change in impedance that exceeds a threshold.

Abstract: A cable tuner front end circuit is disclosed for receiving a radio frequency television input signal and for selectively amplifying the signal in dependence upon a predetermined level of the tuner circuit output signal. The tuner front end circuit having first and second radio frequency paths, where in dependence upon the predetermined level of the output signal, the input signal either propagating along the first path without amplification or the input signal propagating along the second path with low noise amplification. Such that, when amplification is not required the amplifier circuit is disabled thereby offering a savings in tuner circuit power consumption.

Abstract: A cable tuner front end circuit is disclosed for receiving a radio frequency television input signal and for selectively amplifying the signal in dependence upon a predetermined level of the tuner circuit output signal. The tuner front end circuit having first and second radio frequency paths, where in dependence upon the predetermined level of the output signal, the input signal either propagating along the first path without amplification or the input signal propagating along the second path with low noise amplification. Such that, when amplification is not required the amplifier circuit is disabled thereby offering a savings in tuner circuit power consumption.