Abstract: According to one embodiment of the present invention, a power amplifier with an interleaved layout is described. The power amplifier can be a monolithic microwave integrated circuit that includes a first transistor structure (e.g., a power transistor) and a second transistor structure that acts as a current reference. The first transistor structure and the second transistor structure are configured to both be disposed in a first region.

Abstract: The present invention relates generally to the field of frequency modulation, and in particular to dual port frequency modulators. The present invention provides a frequency modulator comprising a phase lock loop circuit (108) for receiving and modulating a carrier signal according to the low frequency component of a modulating signal, the phase lock loop circuit comprising a voltage controlled oscillator (118) for outputting a modulated carrier signal and a loop filter (116) for outputting a steering voltage to the VCO, the VCO having a tank circuit (120) comprising a voltage controlled capacitance (VAR1). The frequency modulator also comprises an external voltage controlled capacitance (122) which is arranged to modulate its capacitance according to a high frequency component of the modulating signal, the second voltage controlled capacitance being coupled to the tank circuit.

Abstract: An amplifier (1) having an amplifier transistor (Tr1) with a gate (G) and drain (D). A feedback circuit (2) couples the drain (D) to the gate (G). The feedback circuit (2) has a direct current blocking capacitor (C1) and low pass filter (R3,C2) with a rectifier (D1) therebetween. In use, radio frequency signals at the drain (D) are processed by the feedback circuit (2) to provide a direct current bias to the gate(G). This bias is dependent upon variations of the radio frequency signals at the drain (D).