SUPPRESSION OF ELECTROSTATIC NOISE IN ANTENNA SYSTEMS

• US 3,694,754 A
• Filed: 12/28/1970
• Issued: 09/26/1972
• Est. Priority Date: 12/28/1970
• Status: Expired due to Term

• Current Assignee: Tracor Aerospace, Inc.
• Original Assignee: Otto J. Baltzer
• Inventors: Baltzer, Otto J.
• Primary Examiner(s): Mayer, Albert J.
• Application Number:
  US05/101,871
• Time in Patent Office: 638 Days
• Field of Search: 343/701,704,885 325/377,380,382,387,361,473,378,379,381,387,338,340 317/2R,2F 307/93,94 250/199
• US Class Current: 455/287
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference

Abstract

Antenna noise reduction apparatus and method, especially suitable for airborne service, including an antenna discharging circuit for periodically grounding the receiver antenna through a switching system at a frequency substantially higher than the carrier frequency of the radio system with which the receiver operates.

Claims

1. An antenna discharging switching system for a radio receiver for reducing precipitation static, comprising:

an antenna connected to the receiver for receiving the radio carrier with which the receiver operates by being sensitive to the electric field intensity of the radiation field established by the carrier;

switching means, including at least on solid state switching device, for opening and closing a connection between said antenna and the ground potential at a frequency substantially higher than the frequency of said radio carrier; and

pulsing means for operating said switching device.

2. An antenna discharging switching system in accordance with claim 1 wherein said solid state switching device includes a field effect transistor having its drain electrode connected to said antenna and its source electrode connected to said ground potential, and said pulsing means includes a pulse generator for intermittently biasing the gate electrode of said transistor at said substantially higher frequency rate to form a low resistance path from antenna to ground potential.

3. An antenna discharging switching system in accordance with claim 1, wherein said solid state switching device includes a photosensitive transistor, and said pulsing means includes a light source, the light intensity of which varies at said substantially higher frequency rate.

4. An antenna discharging switching system in accordance with claim 1, wherein said solid state switching device includes a positive set of diode switches and a negative set of diode switches, and said pulsing means alternately produces a positive bias signal for gating on said positive set of diode switches and a negative bias signal for gating on said negative set of diode switches.

5. In a radio receiver system including a radio receiver for operating with a radio frequency carrier and an electric field antenna for receiving the radio frequency carrier by being sensitive to the electric field intensity of the radiation field established thereby, the improvement comprising:

switching means, including at least on solid state switching device, for opening and closing a connection between said antenna and the ground potential at a frequency substantially higher than the frequency of said radio carrier, and pulsing means for operating said switching device.