Multi-channel radiometer imaging system

• US 7,221,139 B2
• Filed: 11/16/2005
• Issued: 05/22/2007
• Est. Priority Date: 09/18/2003
• Status: Expired due to Fees

• Current Assignee: Reveal Imaging, LLC
• Original Assignee: Xytrans, Inc.
• Inventors: Ammar, Danny F.
• Primary Examiner(s): Hirshfeld; Andrew H.
• Assistant Examiner(s): NGUYEN, HOAI AN D
• Application Number:
  US11/280,004
• Publication Number:
  US 20070090824A1
• Time in Patent Office: 552 Days
• Field of Search: 324/76.14, 324/76.13, 324/76.12, 324/76.11, 342/351, 374120-122, 250/352, 250/372, 250/250, 343/703
• US Class Current: 324/76.14
• CPC Class Codes: G01K 11/006 using measurement of the effect of a material on microwaves or longer electromagnetic waves, e.g. measuring temperature via microwaves emitted by the object G01K17/003, G01J5/00 take precedence; measuring the effect of a material on X-, gamma- or particle radiation G01K11/30

Abstract

A radiometer system includes a housing and an RF board contained within the housing. Balanced radiometer channels receive an unknown signal and known reference. Each balanced radiometer channel includes at least one quadrature hybrid and amplifier circuit to provide distributed gain and an amplified output signal. A detection circuit receives and detects the amplified output signal forming a detected signal. A controller board is contained within the housing and has an integration circuit and microcontroller that receives the detected signal and performs video signal digitization and conditioning and real-time corrections on any radiometer channels to account for changes in temperature or gain.

Claims

1. A radiometer system, comprising:

a plurality of balanced radiometer channels that receive an unknown signal and known reference, each balanced radiometer channel comprising a MMIC comprising

a first quadrature hybrid as an input having at least one radio frequency (RF) input and parallel signal outputs;

at least one amplifier connected to each signal path output of said quadrature hybrid; and

a second quadrature hybrid as an output connected to each at least one amplifier and having parallel RF outputs, wherein the at least one amplifier provides an equalized amplifier gain;

a detector circuit the receives and detects the amplified output signal forming a detected signal; and

a circuit that receives the detected signal and performs video signal digitization and conditioning and real-time corrections on any radiometer channels to account for changes in temperature or gain.

2. The radiometer system according to claim 1, and further comprising dual RF inputs at the first quadrature hybrid as an input.

3. The radiometer system according to claim 2, wherein said dual RF inputs represent two different polarizations that are divided equally among amplifiers.

4. The radiometer according to claim 1, and further comprising an RF input and reference input at the first quadrature hybrid as an input.

5. The radiometer according to claim 1, and further comprising two amplifiers connected in series in each signal path.

6. The radiometer according to claim 1, and further comprising three amplifiers connected in series in each signal path.

7. The radiometer according to claim 1, wherein the at least one amplifier connected in each signal path comprises a Low Noise Amplifier (LNA).