Noiseless radar detector

• US 5,784,021 A
• Filed: 01/25/1996
• Issued: 07/21/1998
• Est. Priority Date: 01/25/1996
• Status: Expired due to Term

• Current Assignee: Cobra Electronics Corp. (Cedar Electronics Holdings Corp.)
• Original Assignee: Cobra Electronics Corp. (Cedar Electronics Holdings Corp.)
• Inventors: Oliva, David C.
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US08/591,706
• Time in Patent Office: 908 Days
• Field of Search: 342/20, 342/175
• US Class Current: 342/20
• CPC Class Codes: G01S 7/021 Auxiliary means for detecting or identifying radar signals or the like, e.g. radar jamming signals
• CPC Class Codes: H03B 2202/05 Reduction of undesired oscillations through filtering or through special resonator characteristics
• CPC Class Codes: H03B 2202/086 through a frequency dependent coupling, e.g. which attenuates a certain frequency range
• CPC Class Codes: H03B 5/1864 the frequency-determining element being a dielectric resonator
• CPC Class Codes: H03D 2200/009 Reduction of local oscillator or RF leakage
• CPC Class Codes: H03D 9/0641 located in a hollow waveguide

Abstract

A noiseless radar detector with a dielectric resonator to suppress stray electromagnetic radiation generated by a local oscillator within the radar detector is disclosed. The dielectric resonator acts as an RF microwave absorber/attenuator if the resonant frequency of the dielectric resonator corresponds to the frequency of the interference from the local oscillator.

Claims

1. A radar detector, comprising:

receiving means for receiving a modulated microwave signal;

demodulating means for demodulating a desired mixing carrier wave from the microwave signal, wherein said demodulating means comprises;

a local oscillator oscillating at a frequency corresponding to the carrier wave; and

a mixing diode to subtract or add the carrier wave from or to the microwave signal; and

a dielectric resonator detached from said demodulating means having a resonant frequency corresponding to the carrier wave to suppress the carrier wave after the carrier wave is demodulated from the microwave signal.

2. A radar detector as claimed in claim 1, wherein said receiving antenna is a horn antenna.

3. A radar detector as claimed in claim 2, wherein said dielectric resonator is placed within said horn antenna.

4. A radar detector as claimed in claim 1, wherein said dielectric resonator comprises a small ceramic pill.

5. A radar detector as claimed in claim 1, wherein said dielectric resonator is placed between said demodulating means and said receiving means.

6. A radar detector, comprising:

receiving means for receiving a modulated microwave signal;

demodulating means for demodulating a desired mixing carrier wave from the microwave signal, wherein said demodulating means comprises;

a local oscillator oscillating at a frequency corresponding to the carrier wave, wherein said local oscillator generates an interference signal; and

a mixing diode to subtract or add the carrier wave from or to the microwave signal; and

a first dielectric resonator detached from said demodulating means having a resonant frequency corresponding to the interference signal to suppress the interference signal.

7. A radar detector as claimed in claim 6, wherein said first dielectric resonator comprises a small ceramic pill.

8. A radar detector as claimed in claim 6, further comprising:

a second dielectric resonator detached from said demodulating means having a resonant frequency corresponding to the carrier wave to suppress the carrier wave after the carrier wave is demodulated from the microwave signal.

9. A radar detector as claimed in claim 8, wherein said second dielectric resonator is in the form of a small ceramic pill.

10. A radar detector as claimed in claim 8, wherein said receiving antenna is a horn antenna.

11. A radar detector as claimed in claim 9, wherein said first dielectric resonator and said second dielectric resonator are placed within said horn antenna.

12. A radar detector as claimed in claim 8, wherein said first dielectric resonator and said second dielectric resonator are placed between said demodulating means and said receiving means.