Abstract: A circuit arrangement includes a power amplifier stage, a feedback path, a re-combining stage, first and second gain control elements and a control circuit. The first gain control element is formed by an adjustable delay element which is preceded by a constant gain amplifier.

Abstract: A circuit arrangement includes a feedback loop, with a forward path and a feedback path, and a re-combining stage. A measuring circuit is provided to produce a measuring signal derived from a result signal and a feedback signal by linear combination.

Abstract: A transmitter comprises a linearized power amplifier circuit consisting of a power amplifier output stage having a feedback loop connected between its output and input. The feedback loop includes a coupler, a first gain control element and a feedback function stage which collectively determine the loop gain of the amplifier. A second gain control element is provided in the forward gain path of the power amplifier. The first and second gain control elements are controlled so that the product of their gains is constant. As a result the loop parameters remain substantially constant as the power setting is varied.

Abstract: A frequency synthesized multichannel radio apparatus comprising a synthesized tranceiver and a remotely mountable control unit. All the possible channel frequencies available to users in a large geographical area are stored in a PROM mounted in the transceiver said PROM serving as a look-up table. The addresses of those channel frequencies in the PROM which are available to a particular user are stored in an electrically alterable storage means, such as an EAROM or a E.sup.2 PROM, contained in the control unit. In normal operation a channel selector in the control unit selects a particular channel in the electrically alterable storage means which in turn reads-out addresses of predetermined locations in the PROM which supplies data for example synthesizer divide numbers to the frequency synthesizer.