Accession Number : ADD012620

Title :   Transdigitizer for Relaying Signals from Global Positioning System (GPS) Satellites.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Westerfield,Edwin E

Report Date : 11 Nov 1986

Pagination or Media Count : 10

Abstract : The reception, downconversion and retransmission of the 1575.42 MHz Global Positioning System (GPS) satellite signal is accomplished by the following. First, an RF stage comprising of an antenna, filter and preamplifier receiver, filters and amplifies the 1575.42 MHz signals. Following the RF stage, a converter stage, consisting of a lower frequency. Then, an Intermediate Frequency (IF), comprising an IF amplifier, multiplier, bandpass filter and limiter further amplifies and filters the signals to remove the effects of the signals. A final downconverter converts the signal to base band frequency and in a zero crossing detector the signal is amplified and 1 bit quantized. Finally, a local oscillator controls a frequency synthesizer to latch the signal from the zero crosssing detector in a flip flop, which in turns is used to control a quadraphase monitor, whose signals are amplified and transmitter out the transmit antenna. (Patent).

Descriptors :   *PATENTS, *GLOBAL POSITIONING SYSTEM, *DOWN CONVERTERS, *FREQUENCY SYNTHESIZERS, BANDPASS FILTERS, SIGNALS, CONTROL, LOCAL OSCILLATORS, PREAMPLIFIERS, RECEIVERS, ARTIFICIAL SATELLITES, FREQUENCY BANDS, INTERMEDIATE FREQUENCIES, LOW FREQUENCY, MONITORS, PHASE MODULATION

Subject Categories : Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE