Frequency-scanning radiometer

Claim 1

A frequency-scanning radiometer for use in scanning a radiometric beam, said radiometer comprising a dispersive antenna, with at least two ports, a mixer being connected to each port, each mixer being fed by a variable frequency local oscillator, said oscillator being connected to provide the mixer with a drive signal that varies in frequency, there being one mixer and one oscillator for each port, the antenna most efficiently receiving at least two independent beams simultaneously through radiators, each beam being most efficiently received at an angle and a frequency that is completely independent of other beams, said angle varying with the frequency of the drive signal of the mixer for that particular beam, each beam producing an output at each port, with means for detecting and displaying said output.

Claim 10

A method of using a frequency-scanning radiometer having a serpentine antenna with two ports, a mixer being connected to each port, each mixer being fed by a variable frequency local oscillator, each oscillator being connected to provide the mixer for a particular port with a drive signal that varies in frequency, said serpentine having coupling means at each alternate bend to permit reception of a beam in four directions, two through each port, the antenna most efficiently receiving a particular beam at an angle that varies with the frequency of the drive signal to each mixer, one amplifier being connected to each mixer, each amplifier being connected to a detector, each detector being connected to a lowpass filter which in turn is connected to a single summing point which is connected to a single display, said method comprising operating the radiometer simultaneously at two orthogonal polarizations, operating the mixer for Port one so that the frequency varies from (f 1 +IF) to (f 2 +IF) where IF is the intermediate frequency of the radiometer and operating the mixer for Port two so that the frequency varies from approximately (f 2 +IF) to approximately ( f 1 +IF), varying the frequency of the two mixers simultaneously over said ranges of frequency in a pre-determined pattern so that the sum of the frequency of the two mixers at any given time is always equal to f 1 +f 2 +2IF.

Claim 11

A method of using a frequency-scanning radiometer having a serpentine antenna with two ports, a mixer being connected to each port, each mixer being fed by a variable frequency local oscillator, each oscillator being connected to provide the mixer for a particular port with a drive signal that varies in frequency, said serpentine having coupling means at each alternate bend to permit reception of a beam in four directions, two through each port, the antenna most efficiently receiving a particular beam at an angle that varies with the frequency of the drive signal to each mixer, one amplifier being connected to each mixer, each amplifier being connected to a detector, each detector being connected to a lowpass filter which in turn is connected to a single summing point which is connected to a single display, said method comprising operating the radiometer simultaneously at two orthogonal polarizations, operating the mixer for Port one so that the frequency varies from (f 1 +IF) to (f 2 +IF) where IF is the intermediate frequency of the radiometer and operating the mixer for Port two so that the frequency varies from approximately (f 2 +IF) to approximately ( f 1 +IF), varying the frequency of the two mixers simultaneously over said ranges of frequency in a pre-determined pattern so that the sum of the frequency of the two mixers at any given time is always equal to f 1 +f 2 +2IF.

Claim 12

A method of using a frequency-scanning radiometer having a serpentine antenna with two ports, a mixer being connected to each port, each mixer being fed by a variable frequency local oscillator, each oscillator being connected to provide the mixer for a particular port with a drive signal that varies in frequency, the antenna most efficiently receiving a beam through radiators at an angle that varies with the frequency of the drive signal to each mixer, in two directions, one for each port, the radiometer having a display to view the results obtained, said method comprising operating the mixer for Port one so that the frequency varies from f 1 +IF) to (f 2 +IF) where IF is the intermediate frequency of the radiometer and operating the mixer for Port two so that the frequency varies from f 2 ±IF) to (f 1 +IF), varying the frequency of the two mixers simultaneously over said ranges of frequency in a pre-determined pattern so that the sum of the frequency of the two mixers at any given time is always equal to f 1 +f 2 +2IF, and reviewing the results shown on the display.

Claim 13

A method of using a frequency-scanning radiometer having a serpentine antenna with two ports, a mixer being connected to each port, each mixer being fed by a variable frequency local oscillator, each oscillator being connected to provide the mixer for a particular port with a drive signal that varies in frequency, the antenna most efficiently receiving a beam through radiators at an angle that varies with the frequency of the drive signal to each mixer, in two directions, one for each port, the radiometer having a display to view the results obtained, said method comprising operating the mixer for Port one so that the frequency varies from f 1 +IF) to (f 2 +IF) where IF is the intermediate frequency of the radiometer and operating the mixer for Port two so that the frequency varies from f 2 ±IF) to (f 1 +IF), varying the frequency of the two mixers simultaneously over said ranges of frequency in a pre-determined pattern so that the sum of the frequency of the two mixers at any given time is always equal to f 1 +f 2 +2IF, and reviewing the results shown on the display.