共查询到20条相似文献,搜索用时 31 毫秒
1.
2.4 GHz offset-cancelling down-conversion mixer 总被引:1,自引:0,他引:1
Chih-Chun Tang Kun-Hsien Li Shen-Luan Liu 《Electronics letters》2002,38(9):395-396
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 相似文献
2.
Vahidfar M.B. Shoaei O. 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2008,55(3):219-223
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. 相似文献
3.
Youngwook Kim Youngsik Kim Soonghak Lee 《Microwave and Wireless Components Letters, IEEE》2002,12(6):204-205
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 相似文献
4.
Vahidfar M.B. Shoaei O. 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2007,54(12):1062-1066
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. 相似文献
5.
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. 相似文献
6.
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. 相似文献
7.
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. 相似文献
8.
9.
Novel difference-frequency dual-signal injection method for CMOS mixer linearization 总被引:1,自引:0,他引:1
Cheng K.-K.M. Chung-Fai Au-Yeung 《Microwave and Wireless Components Letters, IEEE》2004,14(7):358-360
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. 相似文献
10.
《Microwave Theory and Techniques》1960,8(6):622-627
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. 相似文献
11.
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. 相似文献
12.
An X-Band Balanced Fin-Line Mixer 总被引:1,自引:0,他引:1
《Microwave Theory and Techniques》1978,26(12):1007-1011
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. 相似文献
13.
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 相似文献
14.
Boris S. Karasik William R. McGrath 《Journal of Infrared, Millimeter and Terahertz Waves》1999,20(1):21-32
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. 相似文献
15.
M. L. Oldfield B. N. Ellison B. J. Maddison C. M. Mann B. P. Moyna D. N. Matheson 《Journal of Infrared, Millimeter and Terahertz Waves》1997,18(8):1547-1563
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. 相似文献
16.
Amir Amirabadi Mojtaba Chehelcheraghi Mahmoud Kamarei 《Circuits, Systems, and Signal Processing》2011,30(4):721-739
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. 相似文献
17.
《Microwave Theory and Techniques》1985,33(1):53-56
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. 相似文献
18.
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. 相似文献
19.
Jean-Marie Dieudonné Karl-Ernst Schmegner Bernd Adelseck Wolfgang Schwab Alexander Colquhoun Johannes Selders 《电信纪事》1990,45(5-6):252-258
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. 相似文献
20.
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. 相似文献