Patents Assigned to Microwave Development Labs.
  • Patent number: 4427936
    Abstract: A compact apparatus for the accurate measurement of complex reflection coefficients and VSWR of a device over a bandwidth of an octave or greater by preferably measuring three power levels at detectors associated with the device. The device is formed by the junction of 5 transmission lines two of which are used for receiving a test signal and for transmitting the signal to the device being measured. The other three transmission lines are connected to detector arms each having a detector associated therewith. The techniques of the invention are embodied herein in a waveguide embodiment, a stripline embodiment and a microstrip embodiment of the invention.
    Type: Grant
    Filed: June 22, 1981
    Date of Patent: January 24, 1984
    Assignee: Microwave Development Labs
    Inventors: Gordon P. Riblet, Bertil E. R. Hansson
  • Patent number: 4336974
    Abstract: An improved rotary joint which is embodied, in a preferred version, in an electrical coaxial rotary connector having relatively rotatable male and female housings defining an outer conductor and means defining an inner conductor. One of the housings carries silver-graphite contacts including an outer annular contact associated with the outer conductor and a centrally disposed disc-like contact associated with the inner conductor. Contact between the contacts of the one housing and conductor points on the other housing is provided by a relatively simple contact means in the form of a first centrally disposed bowed spring washer associated with the disc-like contact and an annular spring washer having a plurality of crest contact locations (waves) associated with the outer annular contact. The spring washers are both constructed of a hard conductor material such as berylium copper plated with, for example, silver and then with a tarnish resisting layer such as rhodium or gold.
    Type: Grant
    Filed: February 13, 1980
    Date of Patent: June 29, 1982
    Assignee: Microwave Development Labs. Inc.
    Inventor: Ronald A. Wilson
  • Patent number: 4258435
    Abstract: Bandpass channel filters are connected to a uniform impedance manifold. Immittance compensation is provided in a way that preserves the canonic form of the network while at the same time serving to separate the filters (channels) along the manifold. The manifold forms a phase shifter between each channel which is sufficient to compensate for filter interactions to thereby permit the design of contiguous or non-contiguous channel multiplexers. Design procedures are described for both a frequency independent manifold and a frequency dependent manifold. One design is of a waveguide WR229 manifold triplexer employing 37 MHz bandwidth 6-cavity Chebyshev filters having ripple return loss of 26dB (VSWR=1.1) with center frequencies at 3720, 3800 and 3880 MHz.
    Type: Grant
    Filed: January 8, 1979
    Date of Patent: March 24, 1981
    Assignee: Microwave Development Labs. Inc.
    Inventors: Ralph Levy, John D. Rhodes
  • Patent number: 4174507
    Abstract: A four port magic tee device has three ports defined by an H arm and two parallel side arms which meet at a common junction of the device, and has a fourth (E) port at the junction. Extending over the fourth port is a section of waveguide which acts as a coupling and matching structure by providing a chamber which is coupled to that port. That arrangement enables the E arm of the magic tee device to be reduced to zero length, if desired. In contrast, the E arm of a conventional magic tee of comparable performance must be of some finite length.
    Type: Grant
    Filed: November 30, 1977
    Date of Patent: November 13, 1979
    Assignee: Microwave Development Labs.
    Inventor: Paul T. K. Young
  • Patent number: 4127829
    Abstract: Under non-fault conditions the power from two equal power transmitters A and B having a relative phasing of 90.degree. is combined in the network of this invention to provide at an output thereof a power of A + B. The network preferably comprises two 3db short-slot 90.degree. couplers connected in cascade with the first coupler normally operating and the second coupler shorted or decoupled in the coupling slot region by means of shorting posts or the like. If transmitter B fails this condition is sensed and the second coupler has its associated decoupling means withdrawn so that the couplers form a zero db cross-over coupler delivering the total power of transmitter A to the output. For a failure condition of transmitter A a decoupling means is also associated with the first coupler so the entire network can be decoupled delivering the total power of transmitter B to the output under that condition. With a failure of either transmitter A or B there is the possibility of inoperation of the decoupling means.
    Type: Grant
    Filed: March 28, 1977
    Date of Patent: November 28, 1978
    Assignee: Microwave Development Labs. Inc.
    Inventors: Ralph Levy, Paul T. K. Young
  • Patent number: 4058780
    Abstract: A three-port waveguide circulator has three waveguide arms which meet at a common junction. A transformer step in the form of a Y-shaped ridge is disposed symmetrically at the common junction. This waveguide ridge step preferably supports a quarterwave gyromagnetic element. The step may be formed by cutting slots from a standard transformer step to form the ridge. The resulting ridge structure is of reduced size including reduced length compared to a standard uniform transformer section which is advantageous for certain applications such as in constructing a four-port circulator as disclosed herein. A double ridge step may also be used.
    Type: Grant
    Filed: August 2, 1976
    Date of Patent: November 15, 1977
    Assignee: Microwave Development Labs., Inc.
    Inventor: Gordon Riblet