Network planning aspects of the HeliNet telecommunications architecture

A high frequency amplifier circuit includes a series resonance circuit resonating at a desired frequency, first transistor to the gate of which are applied signals and to the source of which is connected the series resonance circuit, a second transistor to the base of which is applied the output signal from the first transistor, and third and fourth transistors having their emitters connected to the second transistor. The collector of the third transistor is connected to the source of the first transistor. A parallel resonance circuit resonates at the desired frequency. The collector of the fourth transistor is connected to the source of the first transistor via the parallel resonance circuit. An AGC circuit applies AGC voltage to the bases of the third and fourth transistors for the purpose of varying the collector current ratio of both the transistors. Negative feedback is accomplished in the circuit, and output power is obtained from the parallel resonance circuit.