US 5,966,400 A · Receiver

Abstract

Receiver having an RF input for applying an RF input carrier-modulated modulation signal thereto, which receiver is coupled to a multiplier circuit and to a phase-locked loop (PLL) with a signal path incorporating a phase detector, a loop filter, a first dc decoupling circuit and a controlled oscillator having an in-phase and a quadrature output via which local in-phase and quadrature carriers are applied to the multiplier circuit and the phase detector, respectively, and a signal generator for generating a local auxiliary pilot and a pilot detector for detecting the local auxiliary pilot, an output of which is coupled to the controlled oscillator via a low-pass filter. In order to reduce the influence of oscillator radiation and other parasitic crosstalk effects on the dc reduction, an output of the signal generator is coupled to the signal path of the phase-locked loop between an output of the phase detector and a control input of the controlled oscillator, an output of the multiplier circuit is coupled to a first input and the output of the signal generator is coupled to a second input of the pilot detector.

Claims27

Dependent claims

A receiver having an RF input section for receiving an RF input carrier-modulated modulation signal;

a multiplier circuit and a phase-locked loop (PLL) coupled to an output of said RF input section for supplying a baseband signal, said phase-locked loop having a PLL signal path incorporating a phase detector, a loop filter coupled to an output of said phase detector, a first dc decoupling circuit coupling an output of said loop filter to an input of said loop filter, and a controlled oscillator having a control input coupled to the first dc decoupling circuit, said oscillator having an in-phase output and a quadrature output coupled, respectively, to said multiplier circuit and said phase detector via which local in-phase and quadrature carriers are respectively applied;
a signal generator for generating a local auxiliary pilot;
and a pilot detector for detecting the local auxiliary pilot, an output of said pilot detector (PD) being coupled to the control input of the controlled oscillator via a PD signal path including said first dc decoupling circuit and said loop filter, which is a low-pass filter, characterized in that an output of the signal generator is also coupled to said control input of the controlled oscillator, an output of the multiplier circuit is coupled to a first input of the pilot detector, and the output of the signal generator is also coupled to a second input of the pilot detector.

A receiver having an RF input section for supplying a reception signal to a phase locked loop, said phase locked loop comprising:

a controlled oscillator for generating a local in-phase mixing carrier and a local quadrature mixing carrier;
a signal generator coupled to said controlled oscillator for phase modulating said mixing carriers with a local auxiliary pilot signal;
a phase detector for comparing the phase of said reception signal with the phase of said local quadrature mixing carrier;
a dynamic control loop for controlling said controlled oscillator with an ac signal provided by said phase detector, said dynamic control loop comprising a dc decoupling circuit arranged between said phase detector and said controlled oscillator;
a multiplier circuit for multiplying said reception signal with said local in-phase mixing carrier;
and
a static control loop comprising a pilot detector for controlling said controlled oscillator with a dc signal provided by said pilot detector in response to the local auxiliary pilot signal at an output of said multiplier circuit, said pilot detector having a first input coupled to said output and a second input coupled to said signal generator for synchronous detection of said local auxiliary pilot signal.

4 more elements

Dependencies are inferred from the claim text.

Receiver

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Receiver

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Abstract

Claims27