75 results about "Balanced mixer" patented technology

Method and apparatus are provided for linearized balanced signal mixing. A signal mixing circuit (10) for translating a radio frequency (RF) signal is provided comprising an input amplifier (12), a mixer network (14), and an output buffer amplifier (18). The input amplifier (12) is configured to produce an amplified RF signal and cancel an input third-order intermodulation (IM3) distortion in the amplified RF signal with a cross-coupled feedback amplifier (13). The mixer network (14) is configured to produce an intermediate frequency (IF) signal based on the amplified RF signal and a local oscillator signal. The output amplifier (18) is configured to buffer the IF signal and cancel an output IM3 distortion in the IF signal with a cross-coupled feedback amplifier (19). The input amplifier (12) and cross-coupled feedback amplifier (13) also serve as a bias current source for the mixer network (14), thus lowering the supply voltage required for the mixing circuit (10).

A doubly balanced upconverter mixer includes a local oscillator balun circuit comprising juxtaposed foil elements on opposite sides of an insulated substrate with electrical interconnections between the foil elements. An IF balun circuit also comprises series tuned and parallel tuned foil elements on opposite sides of the substrate in juxtaposition to each other. A diode switching network interconnects the baluns. A local oscillator signal is connected to the foil elements of the local oscillator balun circuit, an RF signal is coupled to one foil element of the IF balun circuit and an IF signal is taken from the other foil element of the IF balun circuit. Another embodiment incorporates MESFET type switches, the gates of which are supplied directly with a symmetrical local oscillator signal. This arrangement eliminates the need for the local oscillator balun.

An active balun circuit is provided for single-ended to differential RF signal conversion with enhanced common-mode rejection which suppresses common mode signal and which achieves phase and amplitude balance without sophisticated tuning or compensation methods. The circuit has a single-ended input and balanced output with phase and amplitude balance error less than 2° and 1.2 dB, respectively, measured from 1.5 GHz to 1.8 GHz at 5V supply. When supply voltage drops down to 1.5V, its phase and amplitude balance error remains within 5° and 2 dB, respectively. The circuit achieves a balanced output via an output network which behaves as an impedance matching network for differential mode signal and is grounded for common mode signal. As a result, common mode signal is suppressed and 180-degree phase balance at output is achieved. The circuit has high-linearity (P1 dBin=5 dBm, IIP3=16.6 dBm) and low residual phase noise (<−155 dBc / Hz at 100 kHz and above) which make it suitable as an active balun / buffer amplifier between LO and balanced mixer for base station receiver applications.

An apparatus comprising an amplifier circuit, a tuning circuit and a mixer circuit. The amplifier circuit may be configured to generate an output signal at a first node in response to an input signal received through a second node. A tuning circuit may be (i) coupled between said second node of the amplifier circuit and third node and (ii) configured to adjust an impedance presented to the third node in response to a tuning voltage. A mixer circuit may have a center tap coupled to the third node.

The mixer circuit is a singled ended input to a double balanced high dynamic range mixer with only two base-emitter junctions across the supply. It provides for the use of bondwires to off chip ground as DC block and DC feed elements. The single ended input and differential output balanced mixer is well suited for the input stage of an integrated radio receiver—off chip circuitry is usually single ended, but on chip circuits are usually differential. No off chip differential RF circuits or baluns are required which reduces off chip component count and improves radio performance. The mixer circuit has lower LO drive requirements because of the DC coupled LO port. This results in better radio performance and a smaller die area because of the DC coupled IF port.

An improved double balanced mixer is provided which in one embodiment includes a first balun for receiving a first single input and providing a first balanced output having two ports, a second balun for receiving a second single input and providing a second balanced output having two ports, and a balanced mixer core responsive to the first and second balanced outputs to provide a mixed signal from the first and second single inputs. The first balun includes an RC network coupled between at least one of the ports of the first balanced output and one of ground and a common mode node of the first balun to improve the linearity of the double balanced mixer.

A balanced mixer circuit (300, 400, 500, 600, 700 and 800) in a baseband receiver (202) includes an oscillator circuit (212), a mixer (214 and 215), a digital-to-analog converter (258 and 259) and a digital signal processor (250). The mixer includes CMOS devices (301, 302, 303 and 304). In response to differential outputs from the mixer, the digital signal processor controls the digital-to-analog converter to output bias voltages for the gate of at least one of the CMOS devices of the mixer to compensate for imbalance in the differential output of the mixer that may be caused by mismatch among two or more CMOS devices of the mixer or caused by other reasons, in order to increase second order intercept point of the mixer.

Method and apparatus are provided for linearized balanced signal mixing. A signal mixing circuit (10) for translating a radio frequency (RF) signal is provided comprising an input amplifier (12), a mixer network (14), and an output buffer amplifier (18). The input amplifier (12) is configured to produce an amplified RF signal and cancel an input third-order intermodulation (IM3) distortion in the amplified RF signal with a cross-coupled feedback amplifier (13). The mixer network (14) is configured to produce an intermediate frequency (IF) signal based on the amplified RF signal and a local oscillator signal. The output amplifier (18) is configured to buffer the IF signal and cancel an output IM3 distortion in the IF signal with a cross-coupled feedback amplifier (19). The input amplifier (12) and cross-coupled feedback amplifier (13) also serve as a bias current source for the mixer network (14), thus lowering the supply voltage required for the mixing circuit (10).

A mixer is designed to operate from a low voltage power source connected via a power terminal and ground and includes a balanced mixer circuit with a balanced input port for receiving local oscillator signals, and a pair of input terminals. A biasing circuit includes, an active voltage divider connected between the power terminal and ground to provide higher and lower voltages at first and second voltage taps. A differential driver circuit includes first and second transistors, collectors of which are each direct coupled to separate ones of the pair of input terminals. The first transistor has a base coupled via a capacitor to a single ended receive signal terminal, and an emitter coupled via a first resistor to ground. The second transistor has a base coupled via a capacitor to grounds, and an emitter coupled via a second resistor to the single ended receive signal terminal. The single ended receive signal terminal is also coupled with ground via an impedance element, in one example third resistor. A fourth resistor is connected between the first voltage tap and the base of the second transistor and, a fifth resistor is connected between the second voltage tap and the base electrode of the first transistor.

A phase-linear wide band converter for frequency conversion from a multi-octave baseband (BB) to an RF band or vice versa and utilizing I / Q signal processing. The converter uses a phase-linear power divider / combiner having three ports, an I / Q mixer stage, an I / Q power divider for an I / Q local oscillator (LO) signal, two wide band balanced mixers, and impedance matching circuits. The improved performance over multi-octave bands is due to the mutually adaptation between an active opamp I / Q power divider / combiner at an extended baseband, a single low-pass filter (LPF) having predetermined amplitude and phase characteristics and being inserted in the baseband signal path to or from the active baseband power divider / combiner, and a baseband phase correction stage.

A vehicle speed detection radar design and signal processing method is embodied by a radar design proposal for achieving the comprehensive aims of low price, high performance and small size. A radar is composed of two parts of a radar front end and a high-speed digital signal processor; and the front end of the radar is composed of a transmitting micro-band array antenna, a receiving micro-band array antenna, a voltage control microwave source with a frequency stabilization circuit, a dual-line balanced mixer, a dual-channel Doppler signal amplification-filter circuit and a dual-channel analog-digital conversion circuit. The front end of the radar uses the integrated design on the structure and the electricity, and the high-speed digital signal processor uses the fast discrete Fourier transform and the orthogonal signal processing methods to obtain the target speed value. The micro-band array antenna of the invention has good direction, so the radar can respectively monitor each lane; a radar system has fast response time and can detect the vehicles which excessively exceed the speed limit; the radar system simultaneously has thinner size, good anti-interference performance, low material cost and low processing cost.

A system and method for activating vehicle sensors which are based on inductive loops. A transformer is used to couple the vehicle frame to activation circuitry. Within the activation circuitry, a voltage controlled oscillator which drives the transformer is scanned throughout the required frequency range while a balanced mixer, low-pass filter, and detector are arranged to show the presence of a signal from an inductive loop by the amplitude of the resultant signal at a difference frequency. The voltage controlled oscillator is then made to dwell at or near the frequency of the sensor loop by adjusting so as to keep the amplitude of that low-frequency difference as high as possible.

The invention discloses a novel passive balun structure, wherein a differential signal terminal of the balun structure is connected with a compensation structure; the compensation structure comprisesa phase shifter and a compensation resistor; the phase shifter and the compensation resistor are directly connected; the phase shifter is a left-handed material phase shifter or a right-hand materialphase shifter; two passive balun structures are designed in a passive double-balanced mixer; a single-ended port of the first passive balun structure is connected with a local oscillation signal, thesingle-ended port of the second passive balun structure is connected with a radio frequency signal input / output end, and four differential ports of the two passive balun structures are cross-connectedto a mixing unit; the differential port of the second passive balun structure leads to an intermediate frequency signal output / input end through a filtering / matching circuit. In the case of hardly influencing the balun loss and degree of balance, the port matching degree of the balun and the isolation degree of the differential signals are greatly improved through the compensation structure; andthe improved balun is applied to the balanced mixer, so that the performances of the mixer are improved to a certain extent.

A balanced mixer circuit (300, 400, 500, 600, 700 and 800) in a baseband receiver (202) includes an oscillator circuit (212), a mixer (214 and 215), a digital-to-analog converter (258 and 259) and a digital signal processor (250). The mixer includes CMOS devices (301, 302, 303 and 304). In response to differential outputs from the mixer, the digital signal processor controls the digital-to-analog converter to output bias voltages for the gate of at least one of the CMOS devices of the mixer to compensate for imbalance in the differential output of the mixer that may be caused by mismatch among two or more CMOS devices of the mixer or caused by other reasons, in order to increase second order intercept point of the mixer.

A triple balanced mixer has a compact size and is readily assembled. The triple balanced mixer has a planar substrate that is formed from several layers of low temperature co-fired ceramic. The substrate has a top layer, a bottom layer and inner layers. Vias extend through the substrate. A local oscillator balun and RF balun are located on the inner layers. An intermediate frequency balun is mounted to the top layer. Diode rings are mounted on the top layer. The diode rings are electrically connected to the local oscillator balun, the RF balun and the intermediate frequency balun through the vias.

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.

An RF mixer provides extended dynamic range with reduced noise by utilizing degeneration inductors in the RF input section of a doubly balanced mixer. Degeneration inductors are also utilized in a mixer having a class AB input section. A current mirror in the class AB input section is also inductively degenerated for further noise reduction. The input section is biased by an all-NPN bandgap reference cell which is tightly integrated into the input section so as to reduce the power supply voltage required for the reference cell. The mixer can be optimized for wide input voltage ranges or low distortion.

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 multilayer double spiral 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 3-dimensional double-spiral circuit layout architecture for the layout of two balun circuit units. This feature allows the required layout area to be only about 15% of that of the conventional star-type DBM.

An economical FMCW short distance measuring radar is provided and can measure the distance between a stationary or moving target and the radar. There are two implementation schemes for the radar, in afirst scheme, reception and transmission are carried out by means of one microstrip array antenna, and a circulator is added to isolate a receiving channel from a transmitting channel; and in a second scheme, reception and transmission are carried out by means of two separated antennae. The radar also comprises a microwave power divider, a balanced mixer, a voltage controlled oscillator, a modulation voltage generator, a temperature sensing controller, a synchronous time-base circuit, a reception amplifier, a demodulation filter circuit, an analog-digital converter, a digital signal processor, and a distance data output and display combination. Stability control is carried out on linear frequency modulation according to reference frequency stabilization and frequency modulation width stabilization. A demodulation filtering design scheme is led in the hardware design, and the distance measuring function is expanded. Target distance information is extracted by means of a DSP processor and fast Fourier transformation. The radar outputs target distance data and can also output a target distance distribution map in a radar beam irradiation orientation in a waveform display mode.

An improved double balanced mixer is provided which in one embodiment includes a first balun for receiving a first single input and providing a first balanced output having two ports, a second balun for receiving a second single input and providing a second balanced output having two ports, and a balanced mixer core responsive to the first and second balanced outputs to provide a mixed signal from the first and second single inputs. The first balun includes an RC network coupled between at least one of the ports of the first balanced output and one of ground and a common mode node of the first balun to improve the linearity of the double balanced mixer.

A calibration device (CC) is coupled to a balanced circuit device (MC) comprising first and second outputs respectively provided with first (Z1) and second (Z2) load impedance means. This calibration device (CC) comprises adjusting means (ADM) arranged to adjust said first (Z1) and second (Z2) load impedance means into a load imbalance for linearization purposes, and a coupling means (CM) inserted between the load impedance adjusting means (ADM) and the first and second outputs and arranged to selectively couple the load impedance adjusting means (ADM) to only a chosen one of the first and second outputs, so that the load impedance adjusting means (ADM) is connected in parallel either to the first load impedance means (Z1) or to the second load impedance means (Z2).

A miniaturized dual-balanced mixer circuit based on a double spiral 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 double spiral layout architecture for the layout of two balun circuit units. This feature allows the required layout area to be only about 15% of that of the conventional star-type DBM.

A miniaturized dual-balanced mixer circuit based on a multilayer double spiral 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 3-dimensional double-spiral circuit layout architecture for the layout of two balun circuit units. This feature allows the required layout area to be only about 15% of that of the conventional star-type DBM.

An improved double balanced mixer is provided which in one embodiment includes a first balun for receiving a first single input and providing a first balanced output having two ports, a second balun for receiving a second single input and providing a second balanced output having two ports, and a balanced mixer core responsive to the first and second balanced outputs to provide a mixed signal from the first and second single inputs. The first balun includes an RC network coupled between at least one of the ports of the first balanced output and one of ground and a common mode node of the first balun to improve the linearity of the double balanced mixer.

Disclosed is a NRD waveguide mixer adopting a ring hybrid coupler applicable to a small-sized and high functional millimeter wave receiving / transmitting device. The NRD waveguide has a housing including two parallel conductive plates. The ring hybrid coupler is installed in the housing and has an annular ring formed with first to fourth ports which are radially extended about the annular ring. An oscillating device is connected to the first port so as to generate a local oscillating signal. A rod antenna is connected to the second port so as to receive / transmit a radio frequency signal. A first balanced mixer mount is connected to the third port and is provided with a first Schottky diode. A second balanced mixer mount is connected to the fourth port and is provided with a second Schottky diode. The radio frequency signal and the oscillating signal inputted from the first and second ports are mixed in the ring hybrid coupler to be transformed into an addition signal and a subtraction signal. The addition and subtraction signals are transmitted to the third and fourth ports to switch the Schottky diodes respectively so that an intermediate signal is generated.

The invention discloses a high linearity fully-balanced mixer. The drain of a PMOS transistor PM1 and the drain of a PMOS transistor PM3 are connected to an input signal VRF+; the source of the PMOS transistor PM1 is connected to the source of the PMOS transistor PM4; the source of a PMOS transistor PM3 is connected to the source of a PMOS transistor PM2; the drain of the PMOS transistor PM2 and the drain of the PMOS transistor PM 4 are connected to an input signal VRF-; the gate of the PMOS transistor PM1 and the gate of the PMOS transistor PM2 are connected to a local oscillator signal VLO+; the gate of the PMOS transistor PM3 and the gate of the PMOS transistor PM4 are connected to a local oscillator signal VLO-; the source of the PMOS transistor PM1 is connected to the source of a PMOS transistor PM5; the source of the PMOS transistor PM5 is connected to the inverse input end of an operational amplifier; the drain of the PMOS transistor PM5 is connected to the positive direction input end of the operational amplifier; the gate of the PMOS transistor PM5 is grounded; the source of the PMOS transistor PM2 is connected to the source of a PMOS transistor PM6; the source of the PMOS transistor PM6 is connected to the in-phase input end of the operational amplifier; the drain of the PMOS transistor PM6 is connected to the negative direction output end of the operational amplifier; and the gate of the PMOS transistor PM6 is grounded. The invention is advantaged by improving the linearity of the mixer under low voltage.

The invention relates to a microstrip balance-unbalance (BALUN), concretely a miniaturization microstrip BALUN, aiming to solve the problem that a present BALUN has a too large area. The microstrip BALUN comprises a current conducting plate, a medium substrate and a ground plate which are successively laminated from top to bottom to be integrated; the front portion of the current conducting plate is provided with an L-shaped short circuit microstrip line with a length of 1 / 4 wavelength; the front end of the L-shaped short circuit microstrip line is flush with the front plate edge of the current conducting plate, and the rear portion of the current conducting plate is provided with a U-shaped microstrip line; two ends of the U-shaped microstrip line are both flush with the rear plate edge of the current conducting plate; the central section of the panel of the ground plate is etched with a penetrating I-shaped slit. With a bandwidth of 100.9%, an area of only 0.1 lambda* 0.1 lambda, and amplitude phase imbalance in a work frequency range respectively of 0.6 dB and 3 degree, the microstrip BALUN is suitable for equipment such as a microwave balanced mixer, a frequency multiplication device, a push pull amplifier, an antenna, etc.