MULTI-CHANNEL MULTI-SYSTEM RADIO FREQUENCY UNIT OF A SATELLITE NAVIGATION RECEIVER

摘要

A multisystem radio-frequency unit of navigational satellite receivers and may be used for the simultaneous reception of any combination of navigation signals from multiple navigation systems: The unit is based on the “system-on-chip” technology and includes four identical independently configurable reception channels with a high degree of isolation from interpenetration of a signal and contaminating signals, two heterodyne frequency synthesizers having a single heterodyne signal generation mode for all four channels, a quadrature heterodyne signal driver for quadrature mixers and an automatic intermediate frequency filter band calibration system. Each reception channel includes a quadrature mixer with image channel suppression adapted to select an upper or lower stop band, and a digital-to-analog automatic intermediate frequency gain control system. During operation, any reference frequency from the specified band can be used for receiving the signal, as well as any conversion frequency from the specified band for the quadrature mixers.