Multi-channel multi-system radio frequency unit of a satellite navigation receiver

摘要

A multisystem radio-frequency unit of navigational satellite receivers usable for simultaneous reception of any combination of navigation satellite signals from multiple navigation systems. The unit includes four identical independently configurable reception channels, an automatic intermediate frequency filter band calibration system and two heterodyne frequency synthesizers, forming heterodyne signals for quadrature mixers of reception channels and clock signals for a correlator. Each reception channel includes a two-stage automatic gain control system. During operation, a heterodyne frequency synthesizer is capable of generating any heterodyne frequency using any reference frequency, wherein heterodyne frequency, located either symmetrically or asymmetrically between spectra of received global navigation satellite signals.