Abstract:
In a waveguide-to-microstrip line coupling arrangement, a microstrip line is placed on an outer surface of a wall of a waveguide which is coupled with the microstrip line via a metallic post connected at its one end to a center strip conductor of the microstrip line and is inserted inside the waveguide via through-holes made in a ground plane of the microstrip line and in the wall of the waveguide where the diameter of the through-hole made in the ground plane is made smaller than that of the through-hole made in the wall of the waveguide. The waveguide has a short-circuited end and the metallic post is placed close to the short-circuited end. The coupling arrangement may be used in a microwave frequency converter having an microwave integrated circuit including a local oscillator and a mixer, where the MIC is located on an outer surface of a longitudinal wall extending from a short-circuited end to an open end.
Abstract:
A frequency converter includes a mixer, a local oscillator connected to the mixer by a line which transmits a local oscillator signal to the mixer and a starter circuit for supplying a transient bias current to the mixer for insuring the start of the local oscillations.
Abstract:
A method and apparatus for frequency conversion comprising sampling an input signal having a first frequency with first time delays between samples in an input delay line, and distributing the samples of the input signal in sequence to an output delay line with different time delays between samples than the first time delays, to generate an output signal of different frequency than the input signal.
Abstract:
A microwave mixing circuit comprises a main transmission line having an input port for receiving an input high frequency and an output port, a band pass filter responsive to a local oscillation frequency, first and second band stop filters, and a mixing diode connected to the output port. The local oscillation frequency applied via the band pass filter to the main transmission line is prevented from being transmitted toward the input port because of the first band stop filter, while an image frequency produced by the diode is reflected by the second band stop filter to be applied to the diode.
Abstract:
By inserting a rectangular conductive flat member having uninterrupted straight edges into a waveguide in contact relation of their edge portions to the waveguide walls in parallel with an electric field therein, cut-off frequencies at portions of the waveguide to which the conductive flat member is inserted become higher to form a cut-off region. The conductive flat member is composed of a conductor plate or by evaporating a conductive thick film on a dielectric or magnetic plate. The conductive flat member occasionally lined with a non-conductive flat member is provided with circuit elements such as slots formed by punching and strip lines or semiconductor diodes formed by evaporation, and microwave circuits having various functions such as filter circuits, directional couplers, oscillator circuits, frequency converter circuits, frequency multiplier circuits, switch circuits, phase shifter circuits, etc. are constructed on the conductive flat member by combination of the circuit elements through mutual coupling therebetween. These microwave circuits are coupled to transmission regions of the waveguide adjoining both sides of the cut-off region by circuit elements located at the end portion of the conductive flat member. Accordingly, only by inserting into the waveguide a conductive flat member on which various circuit elements are provided, desired microwave circuits of various kinds are constructed very easily inside the waveguide. Such microwave circuits are small in size and low in transmission loss due to elimination of waveguide converters conventionally used, and are suitable for massproduction due to simplicity of structure and ease of manufacturing and assembling which result from mechanical working technique of high degree being unnecessary.
Abstract:
A mixer circuit using a rat-race constituted by disposing microstrip lines on one surface of a substrate to provide a loop-shaped transmission line and four transmission lines connected to the loop. In the rat-race, two of the four transmission lines are disposed within the loop of the loop-shaped transmission line. A conductor penetrates the substrate at the center of the loop of the loop-shaped transmission line, and a pair of diodes are connected respectively between this conductor and the two transmission lines disposed within the loop so that an intermediate frequency signal obtained by subjecting a high frequency signal to frequency conversion can be derived from the conductor at the other surface side of the substrate.
Abstract:
A diode ring mixer in which a coupling loop between two ferrite spheres is constructed as a double conductor. The coupling loops for the symmetrical input and symmetrical output are branched off in a coupling space halfway their line length.
Abstract:
A balanced mixer and crystal oscillator translates a baseband signal upward in frequency just below the passband of a crystal filter at the output of the mixer. The filter passes only the noise in its passband to a logarithmic amplifier-detector. The DC output of the detector is coupled to a recorder calibrated directly in signal-to-noise ratio of the translated baseband signal. Different width baseband signals (different number of FDM channels) are handled by changing the crystal of the oscillator so that the translated baseband signal remains just below the filter passband.
Abstract:
A waveguide component for use in microwave range or in quasimillimeter wave range such as, for instance, a frequency multiplier or a frequency down converter. The waveguide component comprises a strip line element functioning as an antenna for resonating at least two electromagnetic waves having different frequencies and a semiconductor element of which one end is connected to the strip line. Both the strip line and the semiconductor element are provided onto a dielectric base plate by means of printing circuit technique. The dielectric base plate is mounted in a waveguide in a manner that the strip line element extends parallel to a high frequency electric field in the waveguide. The waveguide component having above construction is able to be miniaturized by the elimination of the conventional tuning circuit elements and due to its improved semiconductor mounting it is suitable to be used in quasi-millimeter wave range.
Abstract:
A high-order mixer uses a full-wave, odd-function, exponential (antisymmetric) nonlinearity to transfer modulation information onto a carrier or reference signal. In one form, a pair of highorder mixers are used in a balanced arrangement to effect comparison of the amplitudes of two high-frequency input signals without regard to the phase of these signals and to provide an output at the reference frequency (or a multiple) which (i) increases monotonically as the difference between the signal amplitudes increases, (ii) reverses phase as the signal amplitude difference reverses, and (iii) becomes zero when the two signal amplitudes are equal. In another example, such a comparator is used for automatic tuning.