Multi-channel sonic receiver with combined time-gain control and heterodyne inputs

• US 4,378,596 A
• Filed: 03/01/1982
• Issued: 03/29/1983
• Est. Priority Date: 07/25/1980
• Status: Expired due to Term

• Current Assignee: Diasonics Delaware Incorporated
• Original Assignee: Diasonics Cardio/Imaging Incorporated
• Inventors: Clark, Lloyd D.
• Primary Examiner(s): Farley, Richard A.
• Application Number:
  US06/353,010
• Time in Patent Office: 393 Days
• Field of Search: 343/5 SM, 367/900, 367/87, 367/99, 367/102, 73/900, 455/232, 455/236, 455/246, 455/247
• US Class Current: 367/87
• CPC Class Codes: G01S 7/52033 Gain control of receivers for seismic signals G01V1/245
• CPC Class Codes: Y10S 367/90 Sonar time varied gain control systems
• CPC Class Codes: Y10S 73/90 Automatic gain control

Abstract

In a receiver for pulsed ultrasonic beams, it is sometimes desirable to translate the received signal to a lower carrier frequency by a heterodyne process. It is also often desirable to vary the receiving channels'"'"' gain during the period when signals are being received from a single transmitted pulse, to compensate for the attenuation of later-arriving signals from a greater distance. To get both the heterodyne and the time-gain control functions in a prior-art receiver of N channels requires 2 mixers in each channel, or 2N mixers. According to the invention, the heterodyne and the time-gain control signals are combined in one master mixer and fed to all the channel mixers. The only N+1 mixers are required.

Claims

1. A multiple channel sonic beam receiver for observing internal organs and other medical applications comprising:

a plurality of signal processing channels, each channel comprising;

(i) a transducer;

(ii) a first amplifier electrically coupled to said transducer and having an output;

(iii) a first analog multiplier electrically coupled to the output of said first amplifier, and having an output;

(iv) a second amplifier coupled to the output of said first analog multiplier and having an output;

a scan control coupled to the outputs of each of said second amplifiers;

a detector coupled to said scan control for detecting signals therefrom;

an output display coupled to said detector for displaying signals received therefrom;

a time gain control generator having an output for generating a time gain control signal;

a superheterodyne generator having an output for generating a superheterodyne signal;

a second analog multiplier having an input coupled to said output of said time gain conrol generator and to the output of said superheterodyne generator and having an output generating a heterodyne signal modulated by the time gain control signal, the output of said second analog multiplier electrically coupled to each of said first analog multipliers.

2. In a multiple channel sonic beam receiver having a plurality of signal processing channels, each channel having a transducer electrically coupled to a first amplifier, a first analog multiplier electrically coupled to the output of said first amplifier, an improvement comprising:

a time gain control generator having an output, for generating a time gain control signal;

a superheterodyne generator having an output for generating a superheterodyne signal;

a second analog multiplier having an input coupled to said output of said time gain control generator and to said output of said superheterodyne generator and an output generating a heterodyne signal modulated by the time gain control signal, said second analog multiplier output electrically coupled to each of said first analog multipliers;

a plurality of second amplifiers respectively coupled to the output of each of the first analog multipliers;

a common scan control coupled to the outputs of each second amplifier to produce output signals;

a detector coupled to said scan control for detecting said output signals; and

an output display coupled to said detector for displaying said output signals,

whereby the signal strength of signals produced by reflections from objects more distant from the receiver is increased and superheterodyne conversion of received signals is accomplished.