Claims
- 1. Apparatus for receiving and processing transmitted electromagnetic waves, comprising:
- first and second spaced antennas;
- a common channel;
- switching means for coupling either said first or said second antenna to said common channel;
- signal processing means for processing the signals on said common channel, said signal processing means including means for generating an automatic gain control (AGC) signal which depends upon the instantaneous level of the signal on the common channel;
- means for detecting the rate of change of said AGC signal;
- means for comparing a signal representative of the rate of change of said AGC signal with a threshold, and for generating a control signal when said signal representative of the rate of change of said AGC signal exceeds said threshold; and
- means for applying said control signal to said switching means to effect the switching to the other antenna.
- 2. Apparatus as defined in claim 1 further comprising means for comparing the signal on said common channel with a predetermined threshold and for generating another control signal in response to said comparison; and means for applying said another control signal to said switching means to further effect switching to the other antenna.
- 3. Apparatus as defined by claim 1 further comprising:
- further comparing means for comparing the signal on said common channel with another predetermined threshold;
- means for generating another control signal when the output of said further comparing means indicates that the signal on said common channel has had a transition to below said another threshold; and
- means for applying said another control signal to said switching means to further effect switching to the other antenna.
BACKGROUND OF THE INVENTION
This is a continuation-in-part of U.S. application Ser. No. 737,510 filed Nov. 1, 1976, now abandoned.
US Referenced Citations (7)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
737510 |
Nov 1976 |
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