CW DOPPLER TRANSCEIVER SYSTEM

• US 3,617,993 A
• Filed: 09/10/1969
• Issued: 11/02/1971
• Est. Priority Date: 09/10/1969
• Status: Expired due to Term

• Current Assignee: Kontron (S&T AG)
• Original Assignee: Bruce Elson Mount, Harold Lee Massie
• Inventors: Massie, Harold Lee, Mount, Bruce Elson
• Primary Examiner(s): Farley, Richard A.
• Application Number:
  US04/856,759
• Time in Patent Office: 783 Days
• Field of Search: 340/1,3,3D 73/194A,67.6-67.9 343/7.7,8
• US Class Current: 367/90
• CPC Class Codes: A61B 8/488 involving Doppler signals
• CPC Class Codes: G01S 15/586 using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets

Abstract

A transceiver system for processing a Doppler signal, utilizing a common transmit-receive transducer driven by a high-frequency RF-square wave amplitude limited signal for eliminating AM transmitter noise, and a receiver for amplitude-demodulating the received RF output of the transducer to provide a Doppler frequency output.

Claims

1. A transceiver system for processing a Doppler signal comprising, common transducer means for directing energy to and receiving energy reflected from a moving surface, transmitter means for driving said transducer means with a high frequency RF square wave amplitude limited signal for eliminating AM transmitter noise, receiver means coupled from said transducer means for amplitudedemodulating signals representative of said reflected energy to provide a Doppler frequency output, and means for providing a high transmitter output impedance as compared with the impedance at said transducer means enabling maximum transfer of reflected energy from said transducer means to said receiver means.

2. A transceiver system for processing a Doppler signal comprising, common transducer means for directing energy to and receiving energy reflected from a moving surface, transmitter means for driving said transducer means with a high frequency RF square wave amplitude-limited signal for eliminating Am transmitter noise, receiver means coupled from said transducer means for amplitude-demodulating signals representative of said reflected energy to provide a Doppler frequency output, said transmitter means including means for generating a high frequency RF sinusoidal waveform, and squaring amplifier means connected from said generator means for detecting the zero crossings of said sinusoidal wave to provide said high frequency RF square wave.

3. Apparatus according to claim 2 wherein said transmitter means further includes a saturable switching amplifier means connected from said squaring amplifier means for amplitude-limiting said high frequency RF square wave.

4. Apparatus according to claim 3 including transformer means for coupling said transmitter means to said transducer means.

5. Apparatus according to claim 2 wherein, said receiver means includes a dual-channel detector coupled to the transducer means, having oppositely poled diodes in parallel paths and coupled to difference means for eliminating AM noise caused by asymmetrical waveforms at the transmitter.

6. A transceiver system for processing a Doppler signal comprising, common transducer means for directing energy to and receiving energy reflected from a moving surface, transmitter means for driving said transducer means with a high frequency RF square wave amplitude limited signal for eliminating AM transmitter noise, and receiver means coupled from said transducer means for amplitude demodulating signals representative of said reflected energy to provide a Doppler frequency output, said receiver means including means for differentiating said amplitude-demodulated signals to provide an output representative of the surface velocity.

7. Apparatus according to claim 6 wherein said receiver means includes envelope detector means coupled to said differentiating means, for performing said amplitude demodulating.

8. A method for processing a Doppler signal resulting from a frequency shift of a carrier signal by reflection from a moving surface comprising the steps of:

driving a common transmit-receive transducer with a high frequency RF square wave amplitude limited signal-minimizing AM-transmitting noise, amplitude-demodulating the reflected energy received by the common transducer to provide a Doppler frequency output, and presenting a high output impedance at the driving stage output, as compared with the transducer impedance to maximize the reflected energy signal transfer from the transducer to be amplitude demodulated.

9. A method according to claim 8 including the step of differentiating the amplitude modulated signal to provide an output representative of the surface velocity.

10. A transceiver system for processing a Doppler signal comprising, common transducer means for directing energy to and receiving energy reflected from a moving surface transmitter means for driving said transducer means with a high frequency RF square wAve amplitude limited signal for eliminating AM transmitter noise, and receiver means coupled from said transducer means for amplitude-demodulating signals representative of said reflected energy to provide a Doppler frequency output, said receiver means including a dual-channel detector coupled to the transducer means, having oppositely poled diodes in parallel paths and coupled to difference means for eliminating AM noise caused by asymmetrical waveforms at the transmitter.