Subharmonic Mixer Research Articles

An Ultra-Broadband Subharmonic Mixer With Distributed Amplifier Using 90-nm CMOS Technology

This paper presents a Ka- to F-band ultra-broadband subharmonic mixer (SHM) using the standard 90-nm CMOS process. The proposed SHM employs a distributed amplifier and antiparallel diode pair configuration to realize wide operation bandwidth from 33 to 103 GHz, low conversion loss from 0.52 to 3.35 dB, good local oscillation (LO)-to-RF isolation greater than 27.7 dB, and high 2LO-to-RF isolation better than 60 dB with a miniature chip dimension of 0.49 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at a 10-dBm LO power level. Using the distributed amplifier technique, the proposed SHM offers significant advantages, such as broad operation bandwidth, good flatness, high port-to-port isolation, and good conversion loss.

Integrated 200–240-GHz FMCW Radar Transceiver Module

We present a 220-GHz homodyne transceiver module intended for frequency modulated continuous wave radar applications. The RF transceiver circuits are fabricated on 3-μm-thick GaAs membranes, and consist of a Schottky diode based transmitter frequency doubler that simultaneously operates as a sub-harmonic down-converting mixer. Two circuits are used in a balanced configuration to improve the noise performance. The output power is > 3 dBm over a 40-GHz bandwidth (BW) centered at 220 GHz, and the receiver function is characterized by a typical mixer conversion loss of 16 dB. We present radar images at 4-m target distance with up to 60-dB dynamic range using a 30-μs chirp time, and near-BW-limited range resolution. The module is intended for applications in high-resolution real-time 3-D radar imaging, and the unit is therefore designed so that it can be assembled into 1-D or 2-D arrays.

Proposal for 60GHz wireless transceiver for the radio over fiber system

Abstract A 60 GHz mm-wave wireless transceiver for radio over fiber (RoF) is proposed, using sub-harmonic mixer and IF digital signal processing. This scheme can overcome LO leakage and I/Q mismatch. Moreover, an effective verification method of co-simulation between VPI and ADS platforms is considered, this gives full play to the respective advantages of them and in this way we can obtain the results. From these results of the designed wireless transceiver measured by frequency and time domain, we find that 1 Gbit/s data signals carried by 60 GHz mm-wave signals can be successfully recovered. Additionally, the isolation and the conversion loss of the mixer are more than 20 dB, less than 17 dB, respectively. Moreover, the output power of the 60 GHz transceiver is nearly linear with different input powers that are more than −30 dB m.

Heterodyne and subharmonic mixing at 0.6 THz in an AlGaAs/InGaAs/AlGaAs heterostructure field effect transistor

We fabricated a two-dimensional-electron-gas field effect transistor with an asymmetric terahertz antenna connected to the channel terminals and a gate length of 1 μm. We investigated frequency mixing in the transistor's channel by measuring, with a quasi-optical setup, the heterodyne, second- and third-order subharmonic mixing signal at 0.592 THz. The dependence on the gate voltage and on the radiation power of both the local-oscillator and the radio-frequency signals was studied for all mixing orders. The conditions for full-plasmonic-mixing are fulfilled in our transistor at room temperature.

A 10-Gbit/s Wireless Communication Link Using 16-QAM Modulation in 140-GHz Band

This paper describes a 140-GHz wireless link whose maximum transmission data rate is 10 Gbit/s. A sub-harmonic mixer and multiplier based on Schottky barrier diodes, a waveguide H ladder bandpass filter, a Cassegrain antenna, and other components have been developed to construct a high-performance transmitting and receiving front end. 16 quadrature amplitude modulation has been adopted to improve the spectrum efficiency to 2.86-bit/s/Hz. A 32-way parallel demodulation architecture based on frequency-domain implementation of the matched filter and timing phase correction is proposed. An adaptive blind equalization algorithm is also realized to enhance the tolerance for channel distortion. The modulated signal is centered at 140.3 GHz with -5-dBm output power. This link succeeded in transmission of a 10-Gbit/s signal over a 1.5-km distance with a bit error rate of 1e-6 in non-real-time mode. The measured 99.99% power bandwidth of the 10-Gbit/s signal is 3.6 GHz. The lowest acceptable signal noise rate per bit (Eb/N0) is 15 dB. This link also transmitted a 2-Gbit/s real-time signal with lowest BER = 1.80e -11.

Design of Low-Power Direct-Conversion RF Front-End With a Double Balanced Current-Driven Subharmonic Mixer in 0.13 $\mu {\rm m}$ CMOS

A 402-MHz fully differential RF front-end was designed and implemented using 0.13 μm CMOS process. This design was targeted for low-power and low-cost direct conversion applications such as short-range radio in biomedical devices. This RF front-end consists of a differential CG-CS LNA with a positiveor negative-feedback technique and a frequency doubler subharmonic quadrature passive mixer. The subharmonic conversion passive mixer driven by current input signals (from a transconductor) and loaded with low impedance is implemented to minimize the LO self-mixing dc-offset and introduces a high linearity. The front-end was implemented on a 0.13 μm CMOS process and occupies 380μm × 330 μm active chip area, which is approximately 50% of that of the conventional front-end. The RF front-end achieves 31 dB conversion gain, 13.6 dB noise figure (NF) and an in-band IIP3 of 3 dBm. The design consumes 2.25 mA from a 1.2 V power supply.

Downconverting Module Architectures for High Performance Multipixel Cameras

Multipixel cameras represent an emerging topology for arrays receivers, improving speed and accuracy of both security scanning systems and radioastronomical sky surveys by means of a matrix of phased elements. Difficulties in the generation and proper distribution to each pixel of the local oscillator signal still limit their use to frequency ranges below a few GHz or at least seriously affect the complexity of the implementable cameras. This work presents a full comparison between two possible system architectures, alternatively based on LO frequency multiplication or subharmonic mixing strategies, aiming to overcome the aforesaid limitations: design and performance of two compact test vehicles in MMIC technology, both operating in the Q-band frequency range with ultrabroadband IF section, are reported.

Design and implementation of a 150 GHz single-channel millimeter wave interferometer on Joint TEXT tokamak

A simple, single-channel millimeter-wave interferometer system has been designed, fabricated, and installed on the J-TEXT tokamak. For the plasma density anticipated on J-TEXT, a solid-state source operating at 150 GHz has been chosen to minimize errors due to both vibration along the beam path and refraction in the plasma. The new aspect of the interferometer design is to use a subharmonic mixer for detection with a frequency doubled 150 GHz source. It employs a single source which is bias-tuned and modulated with a sawtooth wave form up to 100 kHz in order to generate the intermediate frequency. The 12.5 GHz voltage-controlled oscillator is multiplied to 75 GHz before a final doubler raises it to 150 GHz. A portion of the 75 GHZ power is used for the local oscillator (LO) and is directly connected to the LO input of the subharmonic mixer. The phase is evaluated by a digital phase comparator using a software-based algorithm. Detection noise limits the minimum resolvable phase change with the interferometer to ±0.05 fringe, which corresponds to an averaged electron density change along the chord of ±1.1 × 10(17) m(-2). The maximum measurable electron density is expected to be ∼9 × 10(19) m(-3). A comparison of preliminary results from the millimeter wave interferometer with that from the far-infrared hydrogen cyanide laser (wavelength of 337 μm) interferometer shows good agreement during the pulse flat-top period. The millimeter wave interferometer system will be used as a part of the density feedback control system in the future.

Ka-band ultra low voltage miniature sub-harmonic resistive mixer with a new broadside coupled Marchand balun in 0.18-μm CMOS technology

A Ka-band sub-harmonically pumped resistive mixer (SHPRM) was designed and fabricated using the standard 0.18-μm complementary metal-oxide-semiconductor (CMOS) technology. An area-effective asymmetric broadside coupled spiral Marchand balance-to-unbalance (balun) with magnitude and phase imbalance compensation is used in the mixer to transform local oscillation (LO) signal from single to differential mode. The results showed that the SHPRM achieves the conversion gain of −15–−12.5 dB at fixed f IF=0.5 GHz with 8 dBm LO input power for the radio frequency (RF) bandwidth of 28–35 GHz. The in-band LO-intermediate freqency (IF), RF-IF, and LO-RF isolations are better than 31, 34, and 36 dB, respectively. Besides, the 2LO-IF and 2LO-RF isolations are better than 60 and 45 dB, respectively. The measured input referred P1dB and 3rd-order inter-modulation intercept point (IIP3) are 0.5 and 10.5 dBm, respectively. The measurement is performed under a gate bias voltage as low as 0.1 V and the whole chip only occupies an area of 0.33 mm2 including pads.

High-Isolation Millimeter-Wave Subharmonic Monolithic Mixer With Modified Quasi-Circulator

This study presents a 21-40-GHz broadband subharmonic gate-pumped mixer using the standard 0.18-μ m CMOS process. A modified quasi-circulator is monolithically integrated with an nMOS field-effect transistor to perform down-converter mixing while enhancing all port isolations through a broadband operation. The proposed configuration has a chip size of less than 0.9 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The measured results demonstrate a low conversion loss from 8.3 to 14.2 dB, a local oscillation (LO)-to-RF isolation greater than 50 dB, and a high 2LO-to-RF isolation of 48 dB to 65 dB over the 21-40-GHz RF bandwidth at a 10.5-dBm LO power level.

A subharmonic mixer for the 220–325 GHz frequency range

A subharmonic mixer for the 220–325 GHz frequency range

Application of Implicit Space Mapping in Aid of Design of Sub-harmonic Mixer with CMRC Filter

In recent years, the CMRC filter has been an attractive candidate for use in mixer and frequency multiplier circuits to improve the performance due to its low-insertion loss, sharp rejection, shorter size and wider stop-band. However, complex structures, too much variables and inefficient design method hindered its widespread use. In this study, we report on the application of the implicit space mapping algorithm in design of CMRC filter to greatly improve the design efficiency. Finally, a mixer with CMRC filter is designed and fabricated based on Rogers substrate process. The measured performance of this mixer is sufficient for engineering applications.

A 30-GHz Integrated Subharmonic Mixer Based on a Multichannel Graphene FET

A 30-GHz integrated subharmonic mixer based on a single graphene field-effect transistor (G-FET) has been designed, fabricated, and characterized. The mixer is realized in microstrip technology on a 250- μm-high-resistivity silicon substrate. In order to enhance the current on-off ratio, the G-FET utilizes a channel consisting of an array of bow-tie structured graphene, yielding a current on-off ratio of 7. A conversion loss (CL) of 19 ± 1 dB over the frequency range of 24-31 GHz is obtained with a local oscillator (LO) to RF isolation better than 20 dB at an LO power of 10 dBm. The overall minimum CL is 18 dB at 27 GHz. The mixer has a 3 GHz ± 1-dB IF bandwidth, which is achieved with a fixed LO signal of 15 GHz. The mixer linearity is characterized and the highest third-order intercept point is measured to be 12.8 dBm.

A Low Power CMOS Bulk-Controlled Sub-Harmonic Mixer for LTE-Advanced Applications

In this paper, a 3.5 GHz CMOS sub-harmonic mixer for LTE-advanced applications is presented. The mixer with the bulk-controlled technique improves the linearity and mitigates the power of the local oscillator. The proposed mixer is implemented by tsmc 0.18 μm Mixed Signal RF CMOS 1P6M process and consumes 2.2 mA from a 1.2 V supply. The proposed mixer operates at 3.5GHz LTE-advanced bands and achieves maximum input third-order intercept point (IIP3) of 2.3dBm, power conversion gains of 1.3 dB.

Subharmonic Mixing With Field-Effect Transistors: Theory and Experiment at 639 GHz High Above $f_{T}$

We present experimental and theoretical results on subharmonic mixing in field-effect transistors high above the transistor cutoff frequencies <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$f_{T}$</tex></formula> . Analytical expressions for heterodyne and subharmonic mixing are derived considering different coupling conditions. They have to ensure that the charge density oscillations excited in the transistors' channels by the mixing signals overlap spatially. If this is the case, then a high efficiency of the mixing process can be sustained even at frequencies much above cutoff; in fact, the efficiency is predicted to increase with rising frequency when the plasma-wave regime <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\omega\tau\geq 1$</tex></formula> , <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\tau$</tex></formula> being the electron momentum scattering time, is reached. With patch-antenna-coupled zero-drain-bias (passive) mixers, which we have implemented in standard a 150-nm silicon complementary metal–oxide–semiconductor process technology, subharmonic mixing is demonstrated for a signal frequency of 639 GHz and a local-oscillator frequency of 213 GHz (fundamental antenna resonance and its third harmonic). A local-oscillator drive of 8.2 mV yields an amplitude conversion of the electrical voltage of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${-}{\rm 56}~{\rm dB}$</tex></formula> . The experimentally determined conversion fully agrees with the derived theory.

A 38 TO 44 GHZ SUB-HARMONIC BALANCED HBT MIXER WITH INTEGRATED MINIATURE SPIRAL TYPE MARCHAND BALUN

This work presents an active balanced sub-harmonic mixer (SHM) using InP double heterojunction bipolar transistor technology (DHBT) for Q-band applications. A miniature spiral type Marchand balun with five added capacitances for improved control of amplitude and phase balance is integrated with the SHM. The measured results for the SHM demonstrates a conversion gain of 1.2 dB at an RF frequency of 41 GHz with an associated LO power of 5 dBm. The conversion loss remains better than 3 dB from 38 to 44 GHz. The LO to IF isolation is better than 42 dB within the bandwidth of the mixer and confirms the excellent balance of the integrated spiral type Marchand balun. The DC power consumption of the SHM is only 22.5mW under normal mixer operation.

Design of a W-band sub-harmonic mixer by employing microstrip technology

采用微带混合集成电路技术设计了一款W波段二次分谐波混频器.通过分析二级管封装结构引入的寄生参量，提出了一种减小二级管并联寄生电容的方法.为了避免在W波段使用传统分谐波混频器中普遍使用的过孔接地及侧边平行耦合微带线带通滤波器，提出了一种改进型分谐波混频器结构.测试结果表明混频器在本振频率为45 GHz，中频频率为2.4 GHz时单边带变频损耗最小，最小值为8 dB.射频频率在90~100 GHz测试频率范围内，变频损耗的测量值小于10.5 dB.

Guest Editorial THz Sensing: Materials, Devices, and Systems

This Special Issue is dedicated to the use of THz radiation for sensing. Previously known as the sub-mm or far infrared spectral range, the technological difficulties associated with the fabrication of suitable sources and detectors for THz frequencies has, until recently, limited their use to a small number of laboratories. The availability of elements like frequency multiplier stages and photo-conductive switches, to name only a couple, has now permitted a wider scientific and engineering community to pursue a vast range of objectives using THz radiation. Many of the contributions deal with the development and application of complete systems, identifying the fine details of how the potential of THz waves can be harnessed. Approaching the THz domain from a bottom-up rather than a top-down point of view, this Special Issue is also rich in the latest device developments. The highlights include the demonstration of a transistor able to be used as a sub-harmonic mixer in the THz frequency band. This is accompanied by a paper showing that quantum cascade lasers are not only useful sources but can also simultaneously be used as efficient detection devices. The papers contained in this Special Issue show that the THz community is particularly active undertaking a wide range of investigations related to sensing principles and devices. Although THz radiation has been proposed to solve a large range of problems it is not a panacea. It does, however, have some unique properties, and so it has a role to play in satisfying the needs of ever more sophisticated sensing tasks. The future development of THz waves for sensing will without doubt be thanks to the mutual stimulation provided by workers developing new components, gaining a further understanding of physical processes at THz frequencies, and demonstrating applications unique to this domain.

A BROADBAND LOW POWER HIGH ISOLATION DOUBLE-BALANCED SUBHARMONIC MIXER FOR 4G APPLICATIONS

This paper presents a fully integrated broadband low power high isolation subharmonic mixer. The proposed mixer achieves a double-balanced architecture by adopting a single-to-difierential frequency-doubling technique, and improves port-to-port isolations. The mixer fabricated by tsmc 0.18m Mixed Signal CMOS process achieves maximum power conversion gain of 7.1dB, input third-order intercept point (IIP3) of i6:9dBm, input second-order intercept point (IIP2) of 33.5dBm, and single side-band noise flgure of i19:6dB over the 2.3{5.8GHz fourth generation of mobile phone communications standards (4G) frequency band. The LO-RF, LO-IF and RF-IF isolations are 82.8dB, 66.5dB and 62.3dB, respectively. The measured power consumption is 2.95mW at a 1.8V power supply.

Resistive Graphene FET Subharmonic Mixers: Noise and Linearity Assessment

We report on the first complete RF characterization of graphene field-effect transistor subharmonic resistive mixers in the frequency interval <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RF</sub> =2-5 GHz . The analysis includes conversion loss (CL), noise figure (NF), and intermodulation distortion. Due to an 8-nm thin Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> gate dielectric, the devices operate at only ~ 0 dBm of local oscillator (LO) power with an optimum measured CL in the range of 20-22 dB. The NF closely mimics the CL, thus determining the noise to be essentially thermal in origin, which is promising for cryogenic applications. The highest input third-order intercept point is measured to be 4.9 dBm at an LO power of 2 dBm.