Transmit security system for a synthesized transceiver

Abstract

A frequency synthesized transceiver capable of tuning to a plurality of communication channels is disclosed. The transceiver includes a receiver section and a transmitter section which are coupled to the synthesizer which generates the appropriate injection signals to achieve tuning. The frequency synthesizer includes a multiposition switch which accesses various addressable memory locations in a programmable read-only memory where the appropriate divisors are stored to cause tuning of the synthesizer to the appropriate communication channel. A zone selector switch enables grouping and easy retrievability of channels. The divisors are supplied to a single synchronous binary swallow counter which works in conjunction with a dual modulus prescaler to monitor the frequency output of the voltage controlled oscillator. A programmable divider coupled to a reference oscillator source is compared with the output of the synchronous counter in a digital and analog phase detector. The phase detector supplies signals through a loop filter to apply the appropriate voltage to the voltage controlled oscillator. The phase detector includes means to rapid advance the voltage controlled oscillator to cause frequency tuning.

Dependencies are inferred from the claim text.