Abstract: A transceiver includes a harmonic termination circuit that receives a tunable harmonic voltage from a power amplifier control. The harmonic termination circuit includes a variable capacitor that is capable of adjusting its capacitance in response to the tunable harmonic termination voltage to achieve at least two modes of operation. The at least two modes of operation may be EDGE mode and GSM mode. In this embodiment, the harmonic termination circuit allows for linearity specifications of EDGE to be met, while not degrading the efficiency of the transceiver when operating in GSM mode. In one embodiment, the harmonic termination circuit further includes an inductive element in series with the variable capacitor.

Abstract: A transceiver includes a harmonic termination circuit that receives a tunable harmonic voltage from a power amplifier control. The harmonic termination circuit includes a variable capacitor that is capable of adjusting its capacitance in response to the tunable harmonic termination voltage to achieve at least two modes of operation. The at least two modes of operation may be EDGE mode and GSM mode. In this embodiment, the harmonic termination circuit allows for linearity specifications of EDGE to be met, while not degrading the efficiency of the transceiver when operating in GSM mode. In one embodiment, the harmonic termination circuit further includes an inductive element in series with the variable capacitor.

Abstract: A radio frequency (“RF”) circuit configured in accordance with an embodiment of the invention is fabricated on a substrate using integrated passive device (“IPD”) process technology. The RF circuit includes at least one RF signal line section and an integrated RF coupler located proximate to the RF signal line section. The integrated RF coupler, its output and grounding contact pads, and its matching network are fabricated on the same substrate using the same IPD process technology. The integrated RF coupler provides efficient and reproducible RF coupling without increasing the die footprint of the RF circuit.

Abstract: In one embodiment, a semiconductor device (500) includes a buffer layer (504) formed over a substrate (502). An AlxGa1?xAs layer (506) is formed over the buffer layer (504) and has a first doped region (508) formed therein. An InxGa1?xAs channel layer (512) is formed over the AlxGa1?xAs layer (506). An AlxGa1?xAs layer (518) is formed over the InxGa1?xAs channel layer (512), and the AlxGa1?xAs layer (518) has a second doped region formed therein. A GaAs layer (520) having a first recess is formed over the AlxGa1?xAs layer (518). A control electrode (526) is formed over the AlxGa1?xAs layer (518). A doped GaAs layer (524) is formed over the undoped GaAs layer (520) and on opposite sides of the control electrode (526) and provides first and second current electrodes. When used to amplify a digital modulation signal, the semiconductor device (500) maintains linear operation over a wide temperature range.