61results about "Modulation transference by diodes" patented technology

An imaging system includes an RF source, a focal plane array and device for focusing the RF signal from the RF source. The focal plane array includes a plurality of carbon nanotube mixers for capturing RF signals and down-converting the signals to a selected bandwidth and output an output signal. The device focuses the RF signal output from said RF source onto the focal plane array.

A diode mixer comprises a mixer diode section which has a first circuit including an inductor and a capacitor connected in series and a diode connected in parallel with the first circuit and which includes a first connecting portion to which one end of the first circuit and the anode of the diode are connected, and a second connecting portion to which the other end of the first inductor circuit and the cathode of the diode are connected; an LO signal port connected to the first connecting portion via a first branching circuit and receiving an LO signal; an IF signal port connected to the mixer diode section via a second branching circuit; and an RF signal port connected to the mixer diode section through a third branching circuit. The inductor and the capacitive component of the diode constitute a resonant circuit.

In some embodiments, a system may include a passive uniplanar single-balanced millimeter-wave mixer. In some embodiments, a three-port diode-tee IC forming a mixer core is coupled between an end of a slotline balun and a second coplanar balun. The operational bandwidth of a mixer structure is enhanced by optimizing the distance between the mixer diode-tee core and the back-short circuits. The frequency separation of LO and IF signals may be accomplished by means of stand-alone three-port filter-diplexer device. The system may allow wider than a frequency octave operational bandwidth for a frequency converter device all the way into millimeter wave frequencies at the same time as supporting the operational bandwidth for baseband IF signal over more than six frequency octaves. In some embodiments, the system may accomplish a 500 MHz to 34.5 GHz continuous IF bandwidth with RF signal sweeping from 33 GHz to 67 GHz and local oscillator at 67.5 GHz fixed frequency.

A microwave and millimetric wave quartic frequency mixer is composed of a stopping direct coupler, two stage microstrip oper wires, a schottky reverse diode pair, two stage compact microphand resonance units, two microband high-low impedance line low pass filter. Since the used local frequency is 1/4 of the basic wave frequency mixer, its performance is increased greatly, and the compact microband resonance unit can either transfer the local signal and provide RF signal circuit or flexible adjust the idle terminal reactivity load, so as to suppress the idle frequency to reduce frequency conversion loss.

The invention discloses a W-band even-order sub-harmonic mixer, which comprises a radio-frequency broadband band-pass filter, an anti-parallel diode pair, a phase adjusting transmission line, a local oscillator low-pass filter and a duplexer, wherein one end of the local oscillator low-pass filter is connected with a common port of the duplexer while the other end of the local oscillator low-pass filter is connected with the phase adjusting transmission line, and the anti-parallel diode pair is bridged between the radio-frequency broadband band-pass filter and the phase adjusting transmission line. The W-band even-order sub-harmonic mixer realizes mutual isolation of radio-frequency signals, local oscillator signals and intermediate frequency signals by means of the radio-frequency broadband band-pass filter, the local oscillator low-pass filter and the duplexer, and the mixer can realize wide operation bandwidth as the radio-frequency broadband band-pass filter, the local oscillator low-pass filter and the duplexer have wide bandwidth.

Systems, devices and methods are disclosed for suppressing the 2LO frequency spur, output from a mixer. In various exemplary embodiments, a DC bias circuit is electrically connected to provide DC bias to one or more non-linear elements of the mixer. The biasing voltage is used to cause the current-voltage characteristics and/or junction capacitances between non-linear elements to be more symmetric and/or to suppress 2LO leakage currents that form 2LO frequency spurs at the output of the mixer. The non-linear elements may comprise one of: BJT's, diodes, and FET's. The mixer may be one of: a subharmonic mixer; a fundamental resistive mixer; a fundamental subharmonic transconductance mixer; and a fundamental transconductance mixer comprising an anti-parallel diode pair. The system may further be configured to automatically determine an appropriate DC bias voltage level that will improve one of the LO-IF isolation and the LO-RF isolation.

A resistor 8 for dividing a voltage applied to an anti-parallel diode pair 5 for mixing a DC pulsed signal and a local oscillation signal LO is disposed in pulse modulation circuitry. Therefore, the ratio of the output power of an RF pulsed signal outputted to an RF pulse output terminal 7 at the time of the ON state and the output power at the time of the OFF state can be increased.

A FET based double balanced mixer (DBM) that exhibits good conversion gain and IIP3 values and provides improved linearity and wide bandwidth. In one embodiment, a first balun is configured to receive a local oscillator (LO) signal and generate two balanced LO signals that are coupled to two corresponding opposing nodes of a four-node FET ring. A second balun is configured to pass an RF signal on the unbalanced side. The FET ring includes at least four FETs connected as branches of a ring, with the source of each FET connected to the drain of a next FET in the ring. Each FET is preferably fabricated as, or configured as, a low threshold voltage device having its gate connected to its drain, which causes the FET to operate as a diode, but with the unique characteristic of having close to a zero turn-on voltage.

The invention discloses an improved sub-harmonic mixer based on a coplanar waveguide transmission line. The improved sub-harmonic mixer is characterized in that a dielectric substrate is arranged on the inner bottom surface of a main air chamber; a coupling probe, the coplanar waveguide transmission line, a local oscillator matching line and a micro-strip line structure are arranged on the dielectric substrate; the coplanar waveguide transmission line comprises a matching line, a first horizontal transmission line and a local oscillator low-pass filter matching line which are connected in sequence from left to right; the micro-strip line structure comprises a second horizontal transmission line, a third horizontal transmission line, a fourth horizontal transmission line and an intermediate-frequency low-pass filter matching line which are connected in sequence from left to right; the coplanar waveguide transmission line further comprises two grounding lines respectively positioned on the two sides of the matching line; the two grounding lines are connected with the inner wall of the main chamber. The improved sub-harmonic mixer further comprises planar Schottky anti-parallel mixer diodes, wherein an ohmic contact layer of one of the mixer diodes is connected with the front surface, far away from the dielectric substrate, of the matching line, and an ohmic contact layer of the other mixer diode is connected with the front surface, far away from the dielectric substrate, of the grounding line.

The invention belongs to the technical field of nuclear fusion plasma microwave diagnosis and in particular relates to a broadband low-loss high-frequency microwave modulator based on a rectangular waveguide and a broadband amplitude modulation millimeter wave reflection system based on the waveguide modulator. A quartz crystal oscillator B is connected with a power amplifier; the power amplifier is connected with an intermediate frequency input end of the waveguide modulator; a microwave source is connected with a microwave input end of the waveguide modulator; the waveguide modulator is connected with a microwave amplifier; the microwave amplifier is connected with a horn antenna; a microwave detector is connected with a frequency-selecting amplifier; the frequency-selecting amplifier is connected with a down converter A; the quartz crystal oscillator B is also connected with a down converter B; a quartz crystal oscillator A is respectively connected with the down converter A and the down converter B; the down converter A is connected with a band-pass filter A; the band-pass filter A is connected with a phase discriminator; the down converter B is connected with a band-pass filter B; the band-pass filter B is connected with the phase discriminator. According to the system, low-loss ultrahigh-frequency microwave amplitude modulation can be realized.

A mixer, which is a single balanced mixer, includes an LO port for inputting an LO signal, an RF port for inputting an RF signal, an IF port for outputting an IF signal, a balun for converting an unbalanced signal into a balanced signal, and a pair of mixer diodes connected in series. The mixer further includes a high-pass filter for blocking LO and IF signals and passing an RF signal and a low-pass filter for blocking LO and RF signals and passing an IF signal.

A miniaturized dual-balanced mixer circuit based on a trifilar layout architecture is proposed, which is designed for use to provide a frequency mixing function for millimeter wave (MMW) signals, and which features a downsized circuit layout architecture that allows IC implementation to be more miniaturized than the conventional star-type dual-balanced mixer (DBM). The proposed miniaturized dual-balanced mixer circuit is distinguished from the conventional star-type DBM particularly in the use of a trifilar layout architecture for the layout of two balun circuit units. This feature allows the required layout area to be only about 20% of that of the conventional star-type DBM.

A frequency translating device (FTD) includes at least one mixer diode connected to down-convert a radio frequency (RF) to an intermediate frequency (IF) and to up-convert an IF to an RF and a source of direct current (DC) bias that is connected to the mixer diode. The source of DC bias provides DC bias to the mixer diode that moves the voltage applied to the mixer diode closer to the threshold voltage of the mixer diode. The mixer diode is turned on in response to the DC bias and a local oscillator (LO) drive. Because DC bias is applied to the mixer diode, the peak to peak voltage range of the LO drive can be reduced, thereby reducing the voltage-dependent capacitance of the mixer diode, causing the FTD to exhibit improved reciprocity. The FTD can be used in a three-pair measurement system to determine the conversion response of another FTD.

The invention discloses an intelligent water affair data aggregation terminal. The circuit comprises a signal receiving circuit, a delay feedback circuit and an operational amplifier output circuit. The signal receiving circuit receives signals demodulated by the water affair data control terminal to stabilize voltage stabilization by using voltage-regulator tube D1, the delay feedback circuit forms an average circuit by using an operational amplifier AR1, a diode D2, a diode D3 and a capacitor C2; extraction of mean signals, one path of an output signal of the operational amplifier AR1 buffers the signal by using a buffer circuit consisting of a diode D4, a triode Q2 and a capacitor C3; in the second path, a triode Q5 and a capacitor C4 are used to form a time-delay circuit time-delay signal; finally, the two paths of signals are input into a frequency modulation circuit composed of a triode Q3, a triode Q6 and resistors R8-R10 to adjust the signal frequency. A triode Q7 and a triodeQ8 are used to form a push-pull circuit to prevent signal distortion, an operational amplifier output circuit uses an operational amplifier AR2 to amplify signals in the same phase and then outputs the signals, and the problem that the instantaneous transmission throughput of the signals is too large is solved.

The invention relates to a uhf reader, in particular to a uhf reader demodulation circuit, which comprises a 50 ohm microstrip line phase shifting device, a two-way diode mixer circuit and a two-way LC low pass filter; wherein the 50 ohm microstrip line phase shifting device is used for respectively realizing a pi/2 phase shifting on an input carrier signal and an ASK signal; the two-way diode mixer circuit is a voltage-multiplying circuit which is used for mixing the carrier signal and the ASK signal which are subjected to phase shifting by the 50 ohm microstrip line phase shifting device; and the two-way LC low pass filter is used for filtering the carrier signal from a mixing signal and outputting to a difference amplifier. By adopting a simple Schottky diode as a mixing element and designing a mixing circuit into a voltage-multiplying mode to improve receiving sensitivity, the invention simply realizes ASK demodulation and solves the problem of low gain of passive mixing voltage.

The invention relates to a method for generating an ultralow-phase-noise multi-point agile frequency signal, which comprises the following steps of accessing a replaceable comb-shaped spectrum generator, and directly carrying out frequency multiplication on a reference frequency signal through the comb-shaped spectrum generator to obtain a frequency signal; adopting a band-pass filter to completefirst-time frequency selection filtering work; and adopting a switch filter with a plurality of paths of filtering units to filter out required frequency signals according to frequency segments. A comb spectrum generator is introduced to output signals in a direct frequency multiplication mode, phase noise is deteriorated only according to a frequency multiplication coefficient, other phase noisedeterioration factors are not introduced, and an ideal phase noise index can be obtained; meanwhile, by replacing the comb spectrum, changing the reference frequency and replacing the filter frequency, output of frequency signals of different frequency bands can be achieved, and L-KU frequency band ultra-wideband coverage is achieved; the switching speed of the plurality of frequency points is theswitching time of the switch, so that the switching speed is high; the clutter suppression degree is improved, and stray leakage is reduced.

Provided is a frequency mixer including: an oscillator configured to output an LO signal; a first converter configured to convert an input IF signal into different first and second IF signals; a first mixer configured to output a first RF signal in which the first IF signal is mixed with the LO signal and a first leakage signal; a second mixer configured to output a second RF signal in which the second IF signal is mixed with the LO signal and a second leakage signal; and a second converter configured to mix and attenuate the first and second leakage signals and output an RF signal in which the first and second RF signals are mixed, in order to minimize leakage power of an LO signal generated in a local oscillator in a transmitter for a communication system using a high frequency of 70 GHz or higher, such as an E-band.