Microwave signal detector

Claim 2

A microwave signal detector for receiving two frequency bands comprising a common microwave antenna, a waveguide cavity resonator coupled to said antenna, said waveguide cavity resonator having an electrically conductive divider which divides it lengthwise into two compartments, a first pair of lower frequency diodes in said waveguide resonator, a second pair of higher frequency diodes in said waveguide resonator, said first pair of diodes being in a first of said compartments and said second pair of diodes being in the second of said compartments, an oscillator circuit coupled to one of each pair of diodes, a detector circuit coupled to the other of each pair of diodes, and an alarm coupled to the output of said detector circuit.

Claim 3

A signal detector according to claim 1 wherein said common microwave antenna comprises a waveguide horn.

Claim 4

A signal detector according to claim 2 wherein said horn and waveguide resonator are formed as an integral casting.

Claim 5

A signal detector according to claim 1 wherein said diode pairs each comprise a modulator diode and a detector diode.

Claim 6

A signal detector according to claim 4 wherein said lower frequency diodes are X-band diodes and said higher frequency diodes are K-band diodes.

Claim 7

A signal detector according to claim 1 wherein said first diodes and first compartment are larger than said second diodes and said second compartment.

Claim 8

A signal detector according to claim 1 wherein said compartments are of rectangular cross section, said diodes spanning the shorter dimension of the respective compartments.

Claim 9

A signal detector according to claim 7 wherein said diodes in said first compartment are oriented at least approximately 90° with respect to the orientation of the diodes in said second compartment.

Claim 10

A microwave signal detector comprising a housing having a front plate and a back plate, control and alarm means on said front plate, a microwave horn mounted on said back plate, a waveguide cavity resonator coupled to said horn, said waveguide resonator including a larger rectangular cross section compartment communicating with said horn and a smaller rectangular cross section compartment also communicating with said horn, a first pair of diodes comprising a modulator diode and a detector diode extending across the shorter dimension of said larger compartment, a second pair of diodes commprising a modulator diode and a detector diode extending across the shorter dimension of said smaller compartment, an oscillator circuit coupled to both said modulator diodes, and a detector circuit coupling both said detector diodes to said alarm means.

Claim 11

A microwave signal detector comprising a housing having a front plate and a back plate, control and alarm means on said front plate, a microwave horn mounted on said back plate, a waveguide cavity resonator coupled to said horn, said waveguide resonator including a larger rectangular cross section compartment communicating with said horn and a smaller rectangular cross section compartment also communicating with said horn, a first pair of diodes comprising a modulator diode and a detector diode extending across the shorter dimension of said larger compartment, a second pair of diodes commprising a modulator diode and a detector diode extending across the shorter dimension of said smaller compartment, an oscillator circuit coupled to both said modulator diodes, and a detector circuit coupling both said detector diodes to said alarm means.

Claim 12

A signal detector according to claim 9 wherein said alarm means is visible.

Claim 13

A signal detector according to claim 9 wherein said alarm means comprises an audible alarm.

Claim 14

A signal detector according to claim 9 wherein said first pair of diodes have centerlines lying in a plane which is perpendicular to a plane containing the centerlines of said second pair of diodes.

Claim 15

A signal detector according to claim 12 wherein said housing has a stand, said centerline planes forming an angle of at least approximately 45° with a vertical plane when said housing is in an upright position on said stand.

Claim 16

A signal detector according to claim 13 wherein said horn flares to a square open end having its respective corners aligned in horizontal and vertical planes to define a diamond shaped opening at its larger end.

Claim 17

A signal detector according to claim 13 wherein said diodes are aligned longitudinally of said waveguide resonator in their respective compartments, said diodes being spaced by an integral number of a quarter wavelength at the operating frequency of said compartment.

Claim 18

A signal detector according to claim 15 wherein said larger compartment is dimensioned to operate at X-band frequencies and said smaller compartment is dimensioned to operate at K-band frequencies.

Claim 19

A signal detector according to claim 16 wherein said detector circuit comprises a synchronous demodulator coupled to said oscillator circuit.

Claim 20

A signal detector according to claim 17 including a power cord coupled to said circuits and diodes, said cord having a plug at its end adapted to be received in the cigarette lighter receptacle of an automotive vehicle.

Claim 21

A signal detector according to claim 18 wherein said alarm means comprises both a light and a buzzer.