Abstract: Briefly, in accordance with one embodiment of the invention, a combiner may include transmission lines to couple a receive port and a transmit port to an antenna at a common junction. Shunt admittance elements may be utilized at the transmit and the receive ports to isolate one of the transmit and the receive ports from the antenna by shunting the at least one of the transmit and the receive ports to a power supply potential such as a ground reference. During a transmit mode, the shunt admittance element at the receive port may shunt the receive port to the power supply potential, thereby isolating the receive port from the antenna. During a receive mode the shunt admittance element at the transmit port may shunt the transmit port to the power supply potential, thereby isolating the transmit port from the antenna.

Abstract: Briefly, in accordance with one embodiment of the invention, a wireless device has an array of antennas. A signal is provided to one of the antenna by two variable gain amplifiers, one of which processes a signal that is shifted in phase compared to the signal processed by the other variable gain amplifier.

Abstract: A technique includes generating a first signal that has a fundamental frequency and modulating an input signal with the first signal. The modulation is tuned to a harmonic of the fundamental frequency to produce a modulated signal that has a carrier frequency near the harmonic.