43results about How to "Reduce frequency conversion loss" patented technology

The invention discloses a terahertz multifunctional device based on an integrated technology. The terahertz multifunctional device comprises a terahertz doubler and a terahertz harmonic mixer. The device is structurally and sequentially provided with an input fundamental wave waveguide micro-strip transition, a micro-strip line short plane, a four-tube-core frequency-multiplication diode, a local oscillator matching circuit, a mixing diode, a radio-frequency matching circuit, an input radio-frequency waveguide micro-strip transition and a medium-frequency low-pass filter from left to right. The number of dielectric substrates is reduced so that circuits can be integrated on one substrate, the number of cavities to be machined is reduced as well, and machining and assembly are made simple; design and machining of waveguide transition are omitted, and the size of the cavities is reduced.

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.

Provided in the invention is a portable terahertz passive type color camera comprising a terahertz type multi-beam quasi-optical mixer having N1*N2 pixels. The terahertz type multi-beam quasi-optical mixer carries out frequency mixing on a received terahertz radio frequency signal and a terahertz type oscillator signal to generate N1*N2-path mixing output signals, wherein the N1 and N2 are natural numbers larger than or equal to 1; and each path of mixing output signal corresponds to one pixel. According to the invention, the terahertz type multi-beam quasi-optical mixer is used as the main receiving and frequency conversion element and the integration level is high; and the two-dimensional large-scale array can be realized well. The size of the whole receiving machine is small and the weight is light. The target identification capability can be improved in a complex background environment; and real-time imaging can be realized. The good resolution ratio and the high sensitivity are realized.

The invention discloses a high-gain and high-isolation millimeter wave double-balance passive subharmonic mixer. The passive subharmonic mixer comprises an active balun radio-frequency input stage, apassive balun local oscillator input stage, a passive subharmonic mixing stage and a transimpedance output stage. Radio-frequency signals amplified by an active balun and local oscillator differentialsignals generated by a passive balun are subjected to subharmonic mixing, and intermediate-frequency signals are output through a transimpedance amplifier. In the mixing stage, local oscillator signals are injected from the source of a transistor, and radio-frequency signals are injected from the grid of the transistor, so that the conversion gain is increased. In the active balun, a cross coupling tube is added on the basis of a cascade differential pair structure to improve the amplitude and phase consistency. In the transimpedance amplifier, a cross coupling structure is utilized to increase the gain, decrease the input and output impedance, improve the input current amplification capability and the output drive capability and further increase the conversion gain. The passive subharmonic mixer has the advantages of being high in conversion gain, high in port isolation and the like, and is suitable for the application scenarios of mixing with single-ended input and differential output.

An 18-40GHz double balanced mixer in structure belongs to the microwave and millimeter wave technical field and relates to a double balanced mixer in star structure. The mixer comprises a double ridge waveguide and a hybrid circuit board and an intermediate frequency output terminal which are arranged on the plane E at the center of the double ridge waveguide. In the invention, the height of the two ridges of the 18-40GHz double ridge waveguide is linearly decreased in a gradient way, thus being convenient for installing diodes and being beneficial to improving impedance matching between a fin line and a coplanar strip line; when leading the intermediate frequency out, an inner conductor passes through a medium substrate and extends to the interior of a cavity and close to the wall of the cavity, so as to improve the symmetrical characteristic of an LO and RF signal field structure, thus improving the balance of four diodes, frequency conversion loss and insulation between an LO signal and an RF signal; a bead is adopted to lead the intermediate frequency out, installation is convenient, and reliability is good; and a boss is additionally arranged at the lead out point of the intermediate frequency at the narrow side of the ridge waveguide, thus being beneficial to improving intermediate frequency bandwidth. The invention has the advantages of wide working band, small size, low frequency conversion loss and high insulation and has a favourable application prospect in an ultra wide band transceiver.

The invention belongs to the technical field of terahertz frequency multiplication, and relates to a terahertz frequency multiplier. An ultra-wideband low-loss full-waveguide double-balanced terahertzfrequency multiplier comprises an input waveguide used for inputting signals in a TEM mode; a frequency multiplier circuit used for carrying out frequency multiplication processing on an input signal to generate a frequency multiplication signal; and an output waveguide for outputting a signal in a TE10 mode, wherein the frequency multiplier circuit is connected between the input waveguide and the output waveguide, the input waveguide is a coplanar waveguide, and the output waveguide is a ridge waveguide. According to the terahertz frequency multiplier, the coplanar waveguide and the ridge waveguide are adopted, so that the working bandwidth of several octaves can be realized, and the problem that the working bandwidth of the frequency multiplier is limited by the rectangular waveguide of the traditional terahertz frequency multiplier is effectively solved; a Schottky diode pair adopts a double-balance four-tube-core structure form based on field symmetrical distribution, so that thebalance is better, the harmonic recovery capability is strong, the harmonic component is small, more energy is distributed to main signals, and the frequency conversion loss is small.

The invention discloses a broadband terahertz mixer with low frequency conversion loss, and aims to achieve high isolation, simple structure, high working frequency, low frequency conversion loss andwide working bandwidth. According to the technical scheme, a quartz circuit cavity penetrates through a radio frequency height reduction waveguide and a local oscillation height reduction waveguide, an anti-parallel terahertz Schottky diode is arranged between a radio frequency direct current ground microstrip line and a radio frequency matching branch knot on the upper surface of a quartz substrate, and the radio frequency direct current ground microstrip line and the radio frequency matching branch knot sequentially pass through a radio frequency transition suspension microstrip line; a local oscillator low-pass filter and a local oscillator matching network are connected in series, the local oscillator transition microstrip penetrates through the local oscillator height reduction waveguide and is connected with the intermediate frequency low-pass filter in series, and finally a frequency mixing signal is output through an intermediate frequency port.

The invention discloses a millimeter wave monolithic quadrature down converter, pertaining to the field of electronic technology and relating to a millimeter wave monolithic quadrature down converter. Based on PHMET technology, the invention introduces a low-noise amplifying unit through a radio-frequency signal RF input port in the existing millimeter wave monolithic quadrature down converter, thus greatly reducing the frequency conversion loss of the whole monolithic quadrature down converter, without increasing the chip area. Simultaneously, wideband circuits such as Lange Coupler, Marchand Balun and the like are adopted to realize the power division of signals, thereby realizing the wideband feature of the whole quadrature down converter. The down converter can be applied to radar systems, communication systems and other systems.

The invention provides a terahertz broadband even harmonic mixer circuit based on a distributed radio frequency loop and a mixer, and the mixer circuit comprises a radio frequency input probe, an anti-parallel diode pair, a cascaded wide stop band high suppression local oscillator filter, a local oscillator input probe, an intermediate frequency filter and an intermediate frequency output port, which are sequentially connected and integrated on a microstrip line. The radio frequency input probe is grounded, and the near radio frequency input end of the antiparallel diode pair is grounded to form a distributed multi-radio frequency loop. According to the circuit, the distributed multi-radio-frequency loop is utilized, the influence of the ground loop on the bandwidth, low frequency conversion loss and other performance of the terahertz even-order mixer is effectively reduced, the local oscillation harmonic clutter is matched through the distributed multi-radio-frequency loop, the influence of the terahertz harmonic clutter is reduced, the bandwidth of the mixer is expanded, and the frequency conversion loss of the mixer is reduced.

The invention provides a bias frequency mixing Schottky diode structure and a semiconductor device, and belongs to the technical field of semiconductor devices. The bias frequency mixing Schottky diode structure comprises a first metal electrode and a second metal electrode, the second metal electrode is divided into an upper sub-electrode and a lower sub-electrode, a first Schottky junction is connected between the first metal electrode and the upper sub-electrode, and the second Schottky junction is reversely connected in parallel between the first metal electrode and the lower sub-electrode. According to the bias frequency mixing Schottky diode structure provided by the invention, the two Schottky junctions are connected in parallel reversely, one ends of the Schottky junctions are connected with the same metal electrode, and the other ends of the Schottky junctions are connected with the two disconnected metal electrodes so that the diode can be biased, and the requirement of a frequency mixer on local oscillation power is reduced; and the difficulty of a local oscillation source is decreased.

A broadband low-frequency-conversion-loss double-balanced mixer chip based on a GaAs technology is characterized in that a local oscillator signal is input from two parallel local oscillator baluns, and the local oscillator signal is converted into four balanced output ports which are respectively connected with four local oscillator impedance matching networks and are used for two Schottky diode mixing cores; meanwhile, a radio frequency signal is input from two radio frequency baluns which are connected in parallel, and the radio frequency signal is converted into four balanced output ports which are respectively connected with four radio frequency impedance matching networks and are used for two Schottky diode frequency mixing cores; an intermediate frequency signal is led out from secondary center taps of the two radio frequency baluns and is output through an intermediate frequency filter network; the structure has the advantages that a frequency mixing product is only one fourth of a single-end frequency mixer product, stray output of the frequency mixer is greatly reduced, the double-balun structure is combined with the local oscillator and radio frequency impedance matching technology, the frequency band width is improved. Meanwhile, frequency conversion loss is reduced, and isolation and linearity are correspondingly improved.

The invention relates to a frequency mixing and harmonic wave amplifying efficient ultra-wideband frequency multiplier which comprises a harmonic wave generator which receives fundamental frequency signals, adjusts the working area of the harmonic wave generator by using external input adjusting voltage according to the frequency band requirement of a frequency source, and generates maximum secondharmonic wave, third harmonic wave and fourth harmonic wave respectively; The first to fourth filters are simultaneously connected to the output end of the harmonic generator; Wherein the first radiofrequency switch and the first power amplifier are sequentially connected; A first mixer; A second radio frequency switch; The third radio frequency switch and the second power amplifier are sequentially connected; The fourth radio frequency switch and the second mixer are sequentially connected; Wherein the fifth radio frequency switch and the third power amplifier are sequentially connected. According to the invention, the active device working in the nonlinear region is utilized to generate harmonic waves, and the plurality of radio frequency switches are adopted to amplify or mix each harmonic wave, and then the co-frequency signals are synthesized, so that the efficient broadband signal output is realized.

The invention discloses a spectrum spreading device based on a dual-port mixer. The spectrum spreading device comprises an input duplexer, a local oscillation frequency multiplier, a local oscillationfilter, a local oscillation amplifier, an output duplexer and a terahertz dual-port mixer. The input duplexer is used for receiving a local oscillation signal output by the frequency spectrograph, and providing a high-frequency local oscillation signal for the terahertz dual-port frequency mixer after the local oscillation signal sequentially passes through the local oscillation frequency multiplier, the local oscillation filter, the local oscillation amplifier and the output duplexer in the local oscillation channel. The terahertz dual-port mixer is used for receiving a terahertz signal fromequipment to be tested, and down-converting the terahertz signal into an intermediate frequency signal through a frequency local oscillator signal; and the output duplexer transmits the intermediatefrequency signal to the frequency spectrograph for analysis and display through the intermediate frequency path and the input duplexer. The terahertz waveband frequency spectrograph frequency expansion device provided by the invention has extremely low frequency conversion loss, and can significantly increase the dynamic range of signal measurement of the frequency spectrograph.

The invention discloses a millimeter wave and terahertz sixteenth harmonic mixer based on an avalanche diode. On the basis of a microstrip transmission line and an avalanche diode that is connected to the ground in parallel, the harmonic mixer also includes a coplanar waveguide one-side fin line transmission line, two double-folded compact microstrip resonant cells (DCMRC), and a three-parallel coupling line DC block. The combination of the two double-folded compact microstrip resonant cells (DCMRC) that work at different frequencies helps to effectively improve isolation between a local oscillator and an intermediate frequency port, between a local oscillator and a radio frequency port and between an intermediate frequency port and a radio frequency port, and also enables the reactive load of a terminal at an idle harmonic frequency to be flexibly adjusted. Through the above way, the work frequency of a local oscillator is greatly reduced, the performance is greatly improved, and the cost is effectively reduced.

The invention relates to a terahertz miniaturized subharmonic mixer adopting symmetrical folded open circuit branches. The terahertz miniaturized subharmonic mixer comprises a microstrip circuit composed of a radio frequency circuit, a local oscillator intermediate frequency duplex circuit, an intermediate frequency output circuit and a diode pair. The radio frequency circuit and the local oscillator intermediate frequency duplex circuit are respectively arranged at two ends of the diode pair; the local oscillator intermediate frequency duplex circuit is internally provided with a band elimination filter with a symmetrical folding open circuit branch structure, and the band elimination filter with the symmetrical folding open circuit branch structure is used for blocking a signal with a corresponding frequency and allowing a signal with another frequency to be transmitted at the same time; and the intermediate-frequency output circuit is arranged at the other end of the local oscillator intermediate-frequency duplex circuit and is used for outputting the intermediate-frequency signal to an external device. The band elimination filter adopting the symmetrically folded open-circuit branch structure has the advantages of simple structure, small size, easiness in tuning and the like. The terahertz mixer realized based on the band elimination filter has the excellent performances of wide band, low frequency conversion loss, high return loss and the like.

The invention discloses an improved three-balance frequency mixer comprising two groups of closed loops, each of which is composed of four diodes connected end to end; and three signal ports, namely a local oscillation signal port, a radio frequency signal input port and an intermediate frequency signal output port, wherein the local oscillation signal port provides a local oscillation source signal of an external circuit; the radio frequency signal input port introduces a signal needing frequency conversion; and the intermediate frequency signal output port outputs an intermediate frequency output signal. The local oscillation signal port and the radio frequency signal input port are respectively composed of a local oscillation balun and a radio frequency balun, and the intermediate frequency signal output end is composed of an intermediate frequency extraction structure. The improved three-balance mixer disclosed by the invention can always keep low frequency conversion loss within a wide frequency band and provide relatively high signal isolation at the same time.

The invention provides a portable terahertz semi-active color focal plane camera which comprises a local oscillator reference source, a terahertz multi-beam quasi-optical mixer and W terahertz irradiation source modules, W being the number of pre-obtained colours, and W being a natural number which is equal to or larger than 1. Each terahertz irradiation source module sends terahertz irradiation signals for irradiating on a detected target. Each terahertz irradiation source module comprises a terahertz irradiation signal frequency multiplier and a terahertz antenna. Local oscillator signals generated by the local oscillator reference source are subjected to frequency multiplication through the terahertz irradiation signal frequency multiplier, radiated by the terahertz antenna, and then, irradiates on the detected target. The camera in the invention is small in size, light in weight; capable of improving target identification capability in a complex background environment, excellent in anti-disturbance performance, capable of real-time imaging, and has good resolution and sensitivity.

The invention provides a terahertz broadband third harmonic mixer. The terahertz broadband third harmonic mixer comprises a mixer circuit substrate, a metal cavity and a Schottky diode, wherein the mixer circuit substrate is provided with a waveguide-suspended strip line-microstrip transition structure, a grounding through hole, a suspended strip, an open-circuit line branch knot, a metal ground,an intermediate-frequency low-pass filter, an intermediate-frequency end microstrip line, a fan-shaped probe and a microstrip line, and the metal cavity comprises a radio frequency end waveguide and alocal oscillator end waveguide. The waveguide-suspended strip line-microstrip transition structure is adopted, loss caused by mismatch is reduced, the effective bandwidth is increased, the size is small, machining is easy, and the cost is low.

The invention provides a millimeter-wave two-port sub-harmonic mixer. The mixer comprises a doubled frequency interval rectangular waveguide-anti-pole fin line-microstrip transitional circuit, a radioffrequency local oscillation matching circuit, a low-pass filtering circuit and an anti-parallel diode pair; the doubled frequency interval rectangular waveguide-anti-pole fin line-microstrip transitional circuit, the radio ffrequency local oscillation matching circuit and the low-pass filtering circuit and an anti-parallel diode pair are printed on a dielectric substrate; and the anti-parallel diode pair is carried on a circuit substrate. According to the mixer provided by the invention, a radio frequency signal and a local oscillation signal are input from the same port while an intermediate frequency signal is output by a single port; and the millimeter-wave two-port sub-harmonic mixer has the characteristics of capability of forming the input and output ports in the same straight line, broad working frequency band, low frequency conversion loss, low cost and the like, and can be effectively applied to a millimeter-wave array imaging system.

The invention discloses an ultra-wideband microwave sampling circuit based on a nonlinear transmission line and a sampling method. The sampling circuit comprises a self-biased nonlinear transmission line narrow pulse generation circuit, a slot line-microstrip balun, a sampling gate tube circuit and an intermediate frequency circuit which are connected in sequence, a local oscillator signal entersthe self-biased nonlinear transmission line narrow pulse generation circuit; a series of narrow pulse local oscillation signals are generated; according to the sampling circuit and the sampling methoddisclosed by the invention, a radio frequency signal is converted into a pair of sampling pulses with equal amplitude and opposite phases through the slot line-microstrip balun, the radio frequency signal is sampled on the sampling gate tube circuit and is output after being shaped by the intermediate frequency circuit, so that the sampling of the radio frequency signal is completed, and the sampling circuit and the sampling method disclosed by the invention can realize ultra-wideband frequency coverage from radio frequency to millimeter wave frequency; the self-bias circuit is simple in design, easy to implement and adjust, high in expansibility and low in cost.

The invention discloses a millimeter wave broadband single-balance down converter and a frequency conversion method. An antipodal fin line transition structure comprises two waveguide-microstrip antipodal fin line transitions; the radio frequency local oscillator matching circuit structure comprises two radio frequency local oscillator matching circuits; the reverse T-type diode pair is provided with a b contact, a c contact and an a contact; an input port of the waveguide coupler is connected with a radio frequency signal, and an isolation port is connected with a local oscillator signal; the straight-through port is connected with the b contact after passing through a waveguide-microstrip antipodal fin line transition and a radio frequency local oscillator matching circuit in sequence; the coupling port is connected with the c contact after passing through the other waveguide-microstrip ridge fin line transition and the other radio frequency local oscillator matching circuit in sequence; the a contact is connected with the input end of the low-pass filter through the intermediate-frequency matching circuit, and the intermediate-frequency end of the low-pass filter outputs intermediate-frequency signals. According to the waveguide coupler, the working frequency band width of radio frequency and local oscillator signals is ensured; besides, a radio frequency local oscillator matching circuit and an intermediate frequency matching circuit are arranged to reduce frequency conversion loss and is suitable for a millimeter wave broadband receiver.

The invention relates to a broadband millimeter wave second harmonic mixer, and belongs to the field of radar radio frequency solid-state devices. The mixer comprises a local oscillator input bending waveguide (1), a local oscillator input height reduction waveguide (2), a local oscillator input short circuit surface (3), a radio frequency input height reduction waveguide (4), a radio frequency input short circuit surface (5), a radio frequency direct current grounding (6), a radio frequency waveguide microstrip probe transition (7), a diode matching (8), a Schottky plane diode (9), a local oscillator matching filter (10), a local oscillator waveguide microstrip probe transition (11), an intermediate frequency low-pass filter (12), an intermediate frequency output (13), and a mixer circuit board (14). The device is simple and exquisite in structure, high in isolation degree, wide in working frequency band and low in frequency conversion loss. The problem of low frequency conversion loss realization in a wide frequency band of 84 GHz-94 GHz is effectively solved, the realization of a W-band high-performance and low-cost receiver is ensured, and the requirement of a high-performance test instrument is met.

The invention discloses a multi-channel wideband millimeter-wave mixing system. When a first millimeter-wave signal is input from a radio frequency port of an IQ mixer, the first millimeter-wave signal and a first local oscillator signal are carried out in the IQ mixer. Down-conversion and then input to the bridge, the remaining two ports of the bridge output the first down-conversion signal (useful signal) and the second down-conversion signal (mirror signal) respectively, the RF switch selects the first down-conversion signal to pass through; the intermediate frequency signal from When the port of the RF switch is input, the RF switch selects one of the channels to conduct and transmit the signal to the bridge. The two ports of the bridge output two quadrature signals. The quadrature signal and the second local oscillator signal are in the IQ mixer. Perform up-conversion to obtain a second millimeter-wave signal. The mixing system of the present invention has the bidirectional characteristic of up and down conversion, and at the same time has the selectivity of high and low local oscillators, and can use different single sideband suppression schemes or image frequency interference suppression schemes for specific test scenarios.

The invention discloses a terahertz multifunctional device based on integrated technology, including a terahertz frequency doubler and a terahertz harmonic mixer. Its structure from left to right is: input fundamental waveguide microstrip transition, microstrip line short-circuit surface, four-tube frequency-multiplier diode, local oscillator matching circuit, mixing diode, RF matching circuit, input RF waveguide microstrip transition, IF low pass filter. The number of dielectric substrates is reduced so that the circuit is integrated on one substrate, which also reduces the number of cavities to be processed and makes the processing and assembly simple. On the other hand, the invention reduces the design and processing of waveguide transitions and reduces the cavity size. size.

The invention discloses a novel hybrid integrated circuit for terahertz mixers, and relates to the technical field of transmission devices for electric communication. The novel hybrid integrated circuit comprises quartz substrate circuits, a GaAs substrate circuit, a radio frequency waveguide and a local oscillation waveguide. The GaAs substrate circuit comprises a GaAs substrate and a GaAs terahertz Schottky diode disposed in the GaAs substrate. The front of the GaAs terahertz Schottky diode faces upward. The two ends of a GaAs terahertz Schottky diode pad are respectively integrated with a section of GaAs-based micro strip transmission line or suspended micro strip transmission line, and the GaAs-based micro strip transmission lines or the suspended micro strip transmission lines are respectively and electrically connected with the quartz substrate circuits on the two sides. The integrated circuit reduces the difficulty in device micro assembly. Compared with the current commonly-used hybrid integrated circuit form, the diode assembly precision is improved, the frequency conversion loss of mixers can be reduced, and the test result of mixers is enabled to be closer to the designed result.

The invention discloses a terahertz waveguide biased harmonic mixer, and relates to the technical field of mixers. The mixer comprises a radio frequency waveguide, a local oscillator waveguide and a quartz circuit. Two discrete Schottky diodes are placed at one end of a quartz substrate of the quartz circuit, anodes and anodes of the two Schottky diodes are connected, and cathodes of the two Schottky diodes are grounded through conductive adhesive and stretch across the inclined radio frequency waveguide. The local oscillator waveguide comprises a linear local oscillator waveguide and an inclined local oscillator waveguide. The end part of the inner side of the inclined local oscillator waveguide extends to a quartz substrate of the quartz circuit and stretches across the quartz substrateof the quartz circuit through a quartz E-surface probe, and one end of the quartz E-surface probe is connected with the anode of the Schottky diode through a matched microstrip line. The mixer has theadvantages of being simple in structure, capable of being completely opened under small local oscillation power, convenient to use and the like.