Abstract: The present invention relates to a power amplifier device (10), switchable for at least two separate basic frequency bands, for radio frequency signals with effective suppression of harmonics, where harmonics, corresponding to a first basic frequency band, can be permitted to overlap the frequency range of at least one second basic frequency band. The power amplifier device (10) comprises a power amplifier (1) and an impedance matching circuit (2), switchable by means of a PIN-diode, which provides a load impedance adapted to each individual basic frequency band. Furthermore, the power amplifier device comprises a filter device (3) comprising a fixed low-pass filter (3b) and a switchable filter (3b) acting as an engageable and disengageable notch filter, which comprises at least one reversible PIN-diode.

Abstract: A device for controlling a current to a load by means of mirroring is described. Two transistor units are connected to a common reference point. By driving a current through one of the transistor units, a corresponding current is generated in the second transistor unit. A control unit, connected between the transistors can regulate a voltage difference between transistors. Accordingly, the size of the load attached is determined through mirroring with accuracy and minimal power loss.

Abstract: A power interface circuit (64) is provided that uses an n-channel MOSFET (66) to control the switching of a power supply (46) to a TDMA power amplifier (58). When turned on, the n-channel MOSFET (66) connects the power supply (46) to the power amplifier (58), and when turned off, it disconnects the power supply from the power amplifier. The power interface circuit (64) includes a switch control circuit (70) that controls the switching state of the n-channel MOSFET (66) in response to a switch control signal. The switch control signal has a first binary state during which the n-channel MOSFET (66) is turned off and a second binary state during which the n-channel MOSFET is turned on.