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US 4,000,469 AGranted
Combination waveguide and stripline downconverter
AssigneeBell Telephone Laboratories, Incorporated
InventorThomas Francis McMaster
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AssigneeBell Telephone Laboratories, Incorporated
InventorThomas Francis McMaster
Estimating the term…
A frequency mixer-downconverter which can be tuned as either a single sideband mixer or a double sideband mixer and which has a wide tunable RF bandwidth and low conversion loss is disclosed. A high-frequency input signal is coupled from an input waveguide to a shielded suspended stripline. Two Schottky barrier diodes are connected proximate to the waveguide-to-stripline transition, between the inner conductor and the outer conducting channel of the stripline. The two diodes intermodulate the input signal with a subharmonic pumping signal which is also coupled to the suspended stripline from a waveguide input. An intermediate frequency signal, at a frequency equal to the difference between the input signal and twice the frequency of the pumping signal, is generated as an intermodulation product and transmitted on the suspended stripline to an output. The downconverter can be tuned as either a single sideband mixer or a double sideband mixer by positioning an E-plane waveguide tuning short and an H-plane waveguide tuning short at the transition between the input waveguide and the suspended stripline. For a single sideband mixer the tuning shorts are adjusted to provide at the input waveguide-to-stripline transition a reactive termination at the image frequency and an impedance match at the input signal frequency. The tuning shorts are positioned to provide the same impedance match at both the image frequency and input signal frequency for double sideband tuning.
A mixer for converting an input signal at a first frequency to an output signal at a second frequency which includes an input rectangular waveguide having orthogonal E- and H-planes for receiving said input signal, transmission means having first and second conductors, means connecting said transmission means to said input rectangular waveguide at a point of transition, means for applying a pumping signal to said transmission means, the frequency of said pumping signal being determined by said first and second frequencies, nonlinear means connected between said first and second conductors of said transmission means at a point proximate to said point of transition for mixing said input signal and said pumping signal to generate on said transmission means said output signal at said second frequency, said mixer being characterized by a first tunable shorting means in the E-plane of said input rectangular waveguide at a point proximate to said point of transition, and a second tunable shorting means in the H-plane of said input rectangular waveguide at a point proximate to said point of transition, said first and second shorting means being adaptable for adjusting impedance terminations at said first frequency and at a frequency determined by said first frequency and the frequency of said pumping frequency.
A mixer for downconverting a high-frequency input signal to a signal at an intermediate frequency which includes an input rectangular waveguide having orthogonal E- and H-planes for receiving said input signal, transmission means having first and second conductors, means connecting said transmission means to said input rectangular waveguide at a point of transition, means for applying a pumping signal to said transmission means, the frequency of said pumping signal being determined by the frequency of said input signal and said intermediate frequency, nonlinear means connected between said first and second conductors of said transmission means at a point proximate to said point of transition for intermodulating said input signal and said pumping signal to generate on said transmission means said signal at said intermediate frequency, said nonlinear means also generating an intermodulation product at an image frequency of said input signal, said mixer being characterized by a first tunable shorting means in the E-plane of said input rectangular waveguide at a point proximate to said point of transition, and a second tunable shorting means in the H-plane of said input rectangular waveguide at a point proximate to said point of transition, said first and second tuning short means being positioned to provide predetermined impedance terminations at said input frequency and said image frequency.
A mixer for downconverting a high-frequency input signal to a signal at an intermediate frequency comprising an input rectangular waveguide having orthogonal E- and H-planes for receiving said input signal, transmission means having first and second conductors, means connecting said transmission means to said input rectangular waveguide at a point of transition, said second conductor of said transmission means being connected to the walls of said input rectangular waveguide at said point of transition to form an equal potential surface, means for applying a pumping signal to said transmission means, the frequency of said pumping signal being determined by the frequency of said input signal and said intermediate frequency, nonlinear means connected between said first conductor of said transmission means and said equal potential surface at a point proximate to said point of transition for intermodulating said input signal and said pumping signal to generate on said transmission means said signal at said intermediate frequency, said nonlinear means also generating an intermodulation component at the image frequency of said input signal, a first tunable shorting means in the E-plane of said input rectangular waveguide at a point proximate to said point of transition, and a second tunable shorting means in the H-plane of said input rectangular waveguide at a point proximate to said point of transition, said first and second tunable shorting means being positioned to provide predetermined impedance terminations at said image frequency and said input signal frequency.
Dependencies are inferred from the claim text.