2.4 GHz offset-cancelling down-conversion mixer

A down-conversion mixer utilising the offset-cancelling technique increase the carrier-to-noise ratio (CNR) is presented. The proposed offset-cancelling mixer has been fabricated in a 0.35 μm CMOS process and it can convert the 2.4 GHz RF signal to the 280 MHz IF one with 12 mW power consumption including the buffer. Compared with the non-offset-cancelling mixer, the proposed offset-cancelling mixer has the lower noise level. Experimental results show that the offset-cancelling mixer provides 45 dB CNR better than 34 dB CNR of the mixer without the offset-cancelling technique     

A High IIP2 Mixer Enhanced by a New Calibration Technique for Zero-IF Receivers

The second-order intercept point (IP2) performance of direct conversion receivers is limited by the second-order nonlinearity of the mixer. A new technique which is based on calibrating mixer by injecting a programmable nonlinear current into the mixer output is introduced in this paper. The proposed calibration technique can be used in multistandard mixers. A CMOS mixer demonstrating the performance for Universal Mobile Telecommunication System application and working with supplies as low as 1 V is designed in a 65-nm technology. The simulation results show that the mixer IIP2 is improved more than 25 dB while the mixer current consumption is increased less than 1 mA. The calibration circuit is low noise not to affect the mixer noise figure.     

Linearized mixer using predistortion technique

A predistortion technique has been proposed to reduce intermodulation distortion (IMD) generated from the conversion process of a mixer. In this technique, the IMD generated from a mixer in the IF band was cancelled by the controlled RF error signal, which is generated by a predistorter. The magnitude and phase of the RF error signal were properly adjusted through a vector modulator. This linearization technique has been verified by experiment of a down conversion mixer in the cellular band. A two tone test has been performed at the frequency of 836 MHz with 442 kHz separation. The results show that this method improves about 16 dB of IMD3 at -18 dBm IF output power in 10 MHz frequency band and increases about 3.5 dB of P1 dB of the mixer. Simple topology and good performance in linearization of IF signals renders this technique suitable for highly linear frequency conversion in communication systems     

A New IIP2 Enhancement Technique for CMOS Down-Converter Mixers

The design of a CMOS mixer for cellular phone and 3G applications is challenging because of tough linearity and noise requirements. A new technique for second-order input intercept point (IIP2) enhancement of CMOS down-converter mixers is introduced in this brief. The technique is based on canceling second-order intermodulation components generated in input pseudodifferential transconductor, by injecting a nonlinear current to the mixer. Since this current is controlled by a high bandwidth feedback loop, the cancellation technique can be used in multistandard mixers for high channel bandwidth applications like UMTS and IEEE802.11 as well as GSM. A CMOS mixer demonstrating the performance for UMTS standard is designed in a 65-nm technology which can work with supplies as low as 1 V. The simulation results show that the differential and common mode IIP2 of the mixer are improved about 22 and 29 dB, respectively, while cancellation circuit consumes less than 3.3 mA. The other mixer parameters such as noise figure are not affected by the proposed technique.     

Mélangeur équilibré dans la bande de 26,5 à 40 GHz en technologie de la ligne à ailettes

The fin line technique has been used in a balanced 27.25–29.75 GHz mixer with a 3.75 GHz intermediate frequency. The performance of essential mixer circuits elements is presented. The mixer has an available conversion loss of 5.8 ± 0.8 dB. The mixer is tunable by variable shorts.     

A 0.18μm CMOS Gilbert low noise mixer with noise cancellation

正This paper presents a broadband Gilbert low noise mixer implemented with noise cancellation technique operating between 10 MHz and 0.9 GHz.The Gilbert mixer is known for its perfect port isolation and bad noise performance.The noise cancellation technique of LNA can be applied here to have a better NF.The chip is implemented in SMIC 0.18μm CMOS technology.Measurement shows that the proposed low noise mixer has a 13.7-19.5 dB voltage gain from 10 MHz to 0.9 GHz,an average noise figure of 5 dB and a minimum value of 4.3 dB.The core area is 0.6 x 0.45 mm~2.     

Low-power highly linear UWB CMOS mixer with simultaneous second- and third-order distortion cancellation

A 3.1-4.8 GHz mode-1 UWB CMOS mixer that utilizes simultaneous second- and third-order distortion cancellation is presented. The scheme is based on a new derivative superposition, employing PMOS as an auxiliary FET to cancel the second- and the third-order nonlinear currents of common-source transconductance in the mixer and gives rise to low-distortion operation for a broad range of gate-source voltage. Full Volterra series analysis of the proposed transconductance is reported to examine the effectiveness of the new technique. Simulations in a 0.13 μm CMOS technology demonstrate that IIP3 and IIP2 of the proposed mixer have 18 and 10 dB improvements, respectively, compared with conventional Gilbert-type mixer with the same power consumption. The robustness of the technique has been verified by Monte Carlo analysis. The mixer has a gain of 12 dB and noise figure of 13 dB, while drawing only 2.5 mA from 1.2 V supply voltage.     

分析非线性电路的谐波平衡法的改进

本文根据分析微波非线性电路的基本方法之一谐波平衡法,提出了一种加速收敛过程的改进方法,并且将其应用于微波混频器的非线性分析。在分析过程中引入了混频二极管非线性特性由时域到频域的简化变换技术,大大加快了计算速度。分析结果与已发表的结果相比较,一致性较好。这种改进的分析方法也可以推广应用于包含多个非线性器件的非线性电路的计算机辅助分析。     

Novel difference-frequency dual-signal injection method for CMOS mixer linearization

This paper presents the application of dual-signal injection technique to the reduction of intermodulation distortion (IMD) level in double-balanced mixer. In this method, "difference-frequency" signal components are optimally fed to the mixer through the biasing circuitry for IMD cancellation. For comparison purposes, the measured performance of a 900-MHz complementary metal oxide semiconductor (CMOS) mixer based upon both single and dual injection approaches is shown.     

A Note on the Optimum Source Conductance of Crystal Mixers

This paper describes an accurate and convenient technique for measuring the match of a crystal mixer. Use is made of the fact that with a proper RF drive level, the fundamental conductance of a mixer crystal may be made equal to the optimum source conductance of the crystal for mixer operation, The required drive level depends on certain crystal parameters and on the image frequency termination of the mixer. Design curves are given which simplify the determination of the proper RF drive level for a wide range of crystal parameters and their condition of image frequency termination.     

A +10-dBm IIP/sub 3/ SiGe mixer with IM/sub 3/ cancellation technique

A third-order intermodulation (IM/sub 3/) cancellation technique using a submixer is proposed for a low-power low-distortion mixer. The IM/sub 3/ cancellation is achieved by summing IM/sub 3/ generated in a main mixer and the submixer, which are almost the same amplitude and opposite phase. The mixer was designed to operate at 870 MHz. The proposed technique reduces IM/sub 3/ by 18 dB with a current increase of about 15% and is suitable for low-power applications. The mixer achieved an input-referred third-order intercept point (IIP/sub 3/) of 10 dBm, a gain of 8.7 dB, and an NF of 9.8 dB and dissipates 30 mW from 2.9 V. The IC is fabricated in a SiGe bipolar transistor with f/sub T/= 30 GHz. The IC occupies 1.44 mm/spl times/1.44 mm.     

An X-Band Balanced Fin-Line Mixer

The fin-line technique has been used in a balanced 9-11-GHz mixer with a 70-MHz intermediate frequency. The mixer without an IF amplifier has an available conversion loss of less than 5 dB with a 3.8-dB minimum and a SSB noise figure of less than 6.9 dB with a 5.3-dB minimum. The mixer is tunable by variable shorts. It is possible to scale the device to millimeter-wave frequencies.     

Mixer for low voltage operation

A very high conversion gain mixer of frequency 350 MHz is designed using the injection-locked technique. The mixer is based on a common-base Clapp oscillator which is free-running at a frequency of 350 MHz. Using the injection-locked technique, the nonlinear resistance of the oscillator is modulated by the injection source which provides negative resistance amplification to the RF signal. It gives conversion gain as high as 30 dB with good noise performance     

Microwave Transmission Technique for Accurate Impedance Characterization of Superconductive Bolometric Mixers

The impedance of the submillimeter superconducting hot-electron bolometer mixer was measured in the range 0.2-4 GHz. A special technique relying on determination of the S ₂₁ transmission parameter of the device was used. Many advantages of the technique (wide frequency range, in situ calibration, low test power, accuracy) are demonstrated. The estimate of the mixer bandwidth from the impedance data using the mixer theory is in good agreement with the results of the direct bandwidth measurements.     

Measurements of the sideband conversion gain ratio of a millimeter-wave heterodyne sub-harmonic mixer using a fourier transform spectrometer

A Fourier transform spectrometer, based on a Martin-Puplett polarisation rotation interferometer and using broad-band blackbody noise sources, has been used to study the sideband response i.e., conversion gain, of a room temperature Schottky diode sub-harmonic mixer operating at 300 GHz. The technique enables the response of the mixer to be characterised and preferentially tuned to one sideband, thereby improving the rejection of unwanted spectral components which can be present in the mixer image sideband.     

High IIP3 and Low-Noise CMOS Mixer Using Non-linear Feedback Technique

A third-order intermodulation cancelation technique using a non-linear feedback is proposed to design a low-power low-distortion mixer in a 65 nm standard CMOS technology. The IM3 cancelation is achieved by estimating distorting error at a non-linear feedback element and subtracting it from the input. The linearization technique is utilized in the input trans-conductance of the mixer. The circuit functionality is analyzed using Volterra series. The covering frequency range of the mixer is 800 MHz to 5 GHz. The technique increases the input-referred third-order intercept point (IIP3) and input 1 dB compression point to +16.4 dBm and −1.87 dBm, respectively. It obtains a gain of 9 dB and an input-referred noise of 1.84 nV/?{}/\sqrt{}Hz while consumes 8.75 mA from 1.2 V supply. The layout of the mixer occupies 0.315 mm × 0.296 mm of silicon area.     

140-GHz Finline Components (Short Papers)

A balanced mixer and a p-i-n diode switch based on finline technique for the frequency range around 140 GHz are described. The mixer exhibits a conversion loss of 7 to 8 dB, whereas the p-i-n diode switch shows an insertion loss of 2 dB and a maximum attenuation of 33 dB.     

基于CMOS工艺的低噪声、高增益混频器

基于TSMC 0.18μm CMOS工艺,设计了一种低噪声、高增益的混频器.通过在吉尔伯特单元中的跨导级处引入噪声抵消技术以降低混频器的噪声;并且在开关管的源级增加电流注入电路的基础上并联一个电容与开关管共源节点处的寄生电容谐振,进一步降低混频器的噪声,增大电路的增益.仿真结果表明,在本振（LO）频率为2.395 GHz,射频（RF）频率为2.4GHz时,混频器的增益为14.2dB,双边带噪声系数为5.9dB,输入三阶交调点为-3.2dBm.混频器工作电压1.8V,直流电流为8mA.     

Conception et réalisation d’un mélangeur monolithique à 60 GHz

The fabrication of a monolithic 60 GHz mixer with Schottky diodes is presented. A diode model has been developped. The mixer performances have been optimized with aCad program based on a harmonic balance technique. The fabricated mixer showed a conversion loss of 6 dB combined with a 3.3 dB double side band noise figure. TheIf frequency was 4.1 GHz.     

General multilayer perceptron demixer scheme for nonlinear blind signal separation

A new technique is presented for instantaneous blind signal separation from nonlinear mixtures using a general neural network based demixer scheme. The nonlinear demixer model follows directly from the general mixer model. A general mixer model is described which includes linear mixtures as a special case. In the second part the general framework for a demixer based on a feedforward multilayer perceptron (FMLP) employing a class of continuously differentiable nonlinear functions is presented. A detailed derivation of the learning algorithm used to adapt the demixer's parameters is given. Cost functions based on both maximum entropy (ME) and minimum mutual information (MMI) have been studied. The performance of the new technique was investigated using various experiments derived from the general mixer model and using real-time data. These studies illustrated the superiority and the generality of the new technique compared with existing methods.