US 4,776,032 AGranted

Repeater for a same frequency with spillover measurement

AssigneeNippon Telegraph and Telephone Corporation

InventorsHitoshi Odate, Hisao Takahashi, Toshio Suzuki, Toshio Nojima, Sadayuki Nishiki, Teruya Fujii

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Abstract

The system for measuring the spillover signal from a transmitter to a receiver in a same frequency repeater or a booster has a frequency conversion device which slightly offsets the transmission frequency from the reception frequency, and a signal detector which measures the offset frequency component in the reception signal. The offset frequency is around 100 Hz, which is higher than the fading frequency, and low enough not to affect the operation of receivers. The measured spillover level is used to control the gain of the repeater, and/or to cancel the spillover signal, so that the repeater has the maximum gain without suffering from oscillation.

Claims10

Dependent claims

A repeater comprising:

a reception antenna for receiving reception radio signals;
an amplifier for amplifying the reception signals thus received at said reception antenna;
a transmission antenna connected to said amplifier, said transmission antenna transmits amplified signals having a same frequency as the reception frequency;
a frequency offset means connected to said amplifier and said transmission antenna, the frequency offset means slightly offsets the transmission frequency from the reception frequency;
and
a signal detector connected to said amplifier and said reception antenna, the signal detector measures an offset component level in the reception signals which shows a spillover level which is an indication of the transmission loss between the transmission antenna and the reception antenna.

3 more elements

Dependencies are inferred from the claim text.