radio with a frequenzsynthetisierer and procedures for phases and / or frequency modulation in a frequenzsynthetisierer

摘要

The radio-communication apparatus is equipped with a frequency synthesizer (12) which contains two phase lock loops, one with a low-pass filter and the other with a high-pass filter. The loop with the low-pass filter fixes the basic frequency of the synthesizer, and the other loop corrects for the phase noise. The modulation frequency is applied to the control terminal (11) and is not perturbed by the phase loops because the modulation frequency is above the cutoff frequency of the low-pass filter. The synthesizer (12) is connected to a reference frequency oscillator (15), and its output via an amplifier (18) and a duplexer (8) to antenna (5). The synthesizer (12) contains a variable frequency oscillator, a frequency and/or phase modulator receiving the modulation frequency signal with a given bandwidth, and an adder, in addition to the two phase lock loops. In second embodiment, the synthesizer (12) contains an additional modulator and a mixer connected between the variable frequency oscillator and the first PLL. The first loop contains a phase comparator and a high-pass filter. The second loop contains a phase comparator, a low-pass filter, and two frequency divisors.