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A low-voltage, low-power, high-conversion-gain, short-range up-conversion Gilbert mixer for the licence-free band (865–867 MHz) in India is presented. In this work, the Gilbert cell transconductance stage is replaced by an inverter amplifier with a resistive feedback current mirror. The current bleeding technique is also applied to attain high conversion gain (CG) and low noise figure (NF). The design is realised in 180 nm CMOS SCL process technology and powered by 0.9 V. The proposed design offers a CG of 26.62 dB and an NF of 6.48 dB@866.5 MHz at the expense of an OIP3 of −3.3 dBm with the total power consumption of 1.94 mW. Its layout occupies a core area of 52 µm × 53 µm. [ABSTRACT FROM AUTHOR]

This paper presents an active down-conversion mixer for wireless local area network applications. The proposed down-conversion mixer is designed for 2–3 GHz radio frequency (RF) band and an intermediate frequency of 100 MHz using RF-TSMC CMOS 0.18 μm technology. A new fully differential Darlington cell is introduced in the RF transconductance stage to effectively suppress third-order nonlinearity. In addition, the conversion gain and noise performance of the proposed mixer are improved by using an active load and current bleeding technique. The proposed mixer has been simulated by Cadence Spectre-RF. Post-layout simulation results show the third-order input intercept point can be improved up to 12.5 dBm by optimum biasing of the Darlington cell. The proposed mixer achieves the high conversion gain of 14.5 dB and the low double side-band noise figure of 4.55 dB at the input frequency of 2.4 GHz. The mixer operates at the supply voltage of 1.8 V with power consumption of 17.4 mW. [ABSTRACT FROM AUTHOR]

Using the derivative superposition and noise cancellation techniques, a high linearity, enhanced conversion gain, and low noise figure (NF) CMOS active mixer is presented for wideband applications. The third-order input intercept point (IIP3) of the proposed mixer is improved by cancelling the intrinsic second-order derivative transconductance (gm″) of the main transistor. This is achieved by using an auxiliary transistor which is biased in the weak inversion region to create gm″ with the same amplitude and opposite sign relative to the main transistor. A linear path consisting of two parallel transistors is utilized to cancel the thermal noise of the input transistors. A constant transconductance (Gm) bias circuit is employed to achieve robust performance against process, voltage and temperature variations. Detailed analysis of the proposed mixer is presented, and extensive simulation results are provided to evaluate the efficiency of the utilized techniques. The simulated mixer operates from 500 MHz to 3.1 GHz RF input frequency. Post-layout circuit-level simulation results using a 90-nm RF CMOS process with Spectre-RF reveal that the IIP3 and conversion gain of the proposed mixer are improved about 6.1 dB and 6.2 dB, respectively, compared to the conventional CMOS active mixer. Also, the NF of the proposed mixer is decreased about 2 dB. The simulated S11 is less than − 12 dB in whole RF range. It consumes 13.9 mW from a single 1.1 V power supply which is approximately 60% more than that of the conventional active mixer. [ABSTRACT FROM AUTHOR]

A W-band (75-110 GHz) down-conversion mixer with CMOS-inverter-based RF transconductance (GM) stage for 94 GHz image radar sensors in 90 nm CMOS is reported. Due to the current bleeding and GM contribution of the upper PMOS transistors of the RF GM stage, a larger load resistance can be adopted and a larger GM can be obtained while keeps the same linearity. This leads to a conversion gain (CG) enhancement. In addition, the second-order term GM (g2) and third-order term GM (g3) of the main NMOS transistors of the RF GM stage can be cancelled by those of the upper PMOS transistors and the auxiliary NMOS transistors of the RF GM stage. This leads to a better linearity. The mixer consumes 8.56 mW and achieves an excellent RF-port input reflection coefficient of − 10 to − 18 dB for frequencies of 88.4-103.4 GHz. In addition, for frequencies of 70-100 GHz, the mixer achieves CG of 13.9-17.5 dB and LO-RF isolation of 40.6-43.5 dB, one of the best CG and LO-RF isolation results ever reported for a down-conversion mixer with operation frequency around 94 GHz. Furthermore, the mixer achieves prominent NF of 16.4 dB and output third-order intercept point of 14.1 dBm at 94 GHz. These results demonstrate that the proposed down-conversion mixer architecture is very promising for 94 GHz image radar sensors. [ABSTRACT FROM AUTHOR]

Abstract The rising internet-of-things applications in home automation, smart wearables, healthcare monitoring demand small, area efficient, high-performance and low power radio frequency (RF) blocks for effective short-range communication. This growing market demand is addressed in this paper by proposing a fully CMOS radio frequency front-end (RFE) exploiting bulk effect. Apart from the primary function of frequency translation, proper circuit performance concerning the linearity, conversion gain, and noise figure is required for low-cost densely integrated transceivers operating in the 2.4 GHz ISM band. The proposed RFE at 2.4 GHz is designed and implemented in UMC 180 nm CMOS process technology with two modes of operation. In high gain mode (Mode-I), the post-layout simulation with SpectreRF shows a peak gain of 30.06 dB, IIP2 at 64.52 dBm, IIP3 at −2.74 dBm and a DSB-NF of 7.68 dB while consuming only 9.24 mW from the 1.8 V supply. In the high linear mode (Mode-II), the RFE achieves a higher IIP3 of 10.78 dBm, IIP2 of 91.56 dBm, the conversion gain of 23.5 dB, DSB-NF of 9.46 dB while consuming a low power of 3.6 mW. The fully CMOS circuit occupies a core area of only 0.0021 mm2. The proposed front-end exhibits a spurious free dynamic range (SFDR) of 81.18 dB ensuring the high dynamic operation of the wireless system. [ABSTRACT FROM AUTHOR]

A 94 GHz down-conversion mixer for image radar sensors using standard 90 nm CMOS technology is reported. The down-conversion mixer comprises a double-balanced Gilbert cell with an LC-tank-oscillator-based RF transconductance stage load for conversion gain (CG) enhancement and noise figure (NF) suppression, two miniature planar baluns for converting the single RF and LO input signals to differential signals, and an IF amplifier. The mixer consumes 9.5 mW and achieves excellent RF-port input reflection coefficient (S) of −27.2 dB at 94 GHz, and S smaller than −10 dB for frequencies of 83.6-110 GHz. That is, RF-port −10 dB input matching bandwidth is greater than 26.4 GHz. In addition, for frequencies of 75-100 GHz, the mixer achieves CG of 4.9-7.9 dB (the corresponding 3-dB CG bandwidth is greater than 25 GHz), LO-RF isolation of 38.5-44.7 dB and NF of 15.4-21.2 dB, one of the best CG, LO-RF isolation and NF results ever reported for a down-conversion mixer with operation frequency around 94 GHz. Furthermore, the mixer achieves an excellent input third-order intercept point of 2.6 dBm at 94 GHz. These results demonstrate the proposed down-conversion mixer architecture is promising for 94 GHz image radar sensors. [ABSTRACT FROM AUTHOR]

A 90-96 GHz down-conversion mixer for 94 GHz image radar sensors using standard 90 nm CMOS technology is reported. RF negative resistance compensation technique, i.e. NMOS LC-oscillator-based RF transconductance (GM) stage load, is used to increase the output impedance and suppress the feedback capacitance C of RF GM stage. Hence, conversion gain (CG), noise figure (NF) and LO-RF isolation of the mixer can be enhanced. The mixer consumes 15 mW and achieves excellent RF-port input reflection coefficient of −10 to −36.4 dB for frequencies of 85-105 GHz. The corresponding -10 dB input matching bandwidth is 20 GHz. In addition, for frequencies of 90-96 GHz, the mixer achieves CG of 6.3-9 dB (the corresponding 3-dB CG bandwidth is greater than 6 GHz) and LO-RF isolation of 40-45.1 dB, one of the best CG and LO-RF isolation results ever reported for a down-conversion mixer with operation frequency around 94 GHz. Furthermore, the mixer achieves an excellent input third-order intercept point of 1 dBm at 94 GHz. These results demonstrate the proposed down-conversion mixer architecture is very promising for 94 GHz image radar sensors. [ABSTRACT FROM AUTHOR]

This study compares the performance of radio frequency (RF) mixers employing independent-gate tunnel field-effect transistors (IG TFETs) based on homo (InAs) and heterojunctions (GaSb-InAs). A RF mixer circuit using double gate TFET of 20 nm is designed with the optimal biases on the two gates. IG TFETs used in the circuit simulation are developed with the help of a look-up table based Verilog-A code. The down conversion of RF mixers are operated at a frequency of 95 GHz. The figures-of-merit (FOM), conversion gain $$(G_{\mathrm {C}})$$ , noise figure (NF) and the average power consumption of the mixer circuits are studied along with the different device parameter variations, gate length $$(L_{\mathrm {g}})$$ , gate oxide thickness $$(T_{\mathrm {ox}})$$ and channel thickness $$(T_{\mathrm {ch}})$$ . Higher $$G_{\mathrm {C}}$$ and lower NF are achieved for heterojunction-based TFET mixers with respect to their parameter variations. An average power consumption of 168 and $$227.5\,{\upmu }\hbox {W}$$ is obtained for homo- and heterojunction-based TFET mixers, respectively. [ABSTRACT FROM AUTHOR]

A 94 GHz down-conversion mixer for image radar sensors using standard 90 nm CMOS technology is reported. The down-conversion mixer comprises a double-balanced Gilbert cell with peaking inductors between RF transconductance stage and LO switching transistors for conversion gain (CG) enhancement and noise figure suppression, a miniature planar balun for converting the single RF input signals to differential signals, another miniature planar balun for converting the single LO input signals to differential signals, and an IF amplifier. The mixer consumes 22.5 mW and achieves excellent RF-port input reflection coefficient of −10 to −35.9 dB for frequencies of 87.6-104.4 GHz, and LO-port input reflection coefficient of −10 to −31.9 dB for frequencies of 88.2-110 GHz. In addition, the mixer achieves CG of 4.9-7.9 dB for frequencies of 81.8-105.8 GHz (the corresponding 3-dB CG bandwidth is 24 GHz) and LO-RF isolation of 37.7-47.5 dB for frequencies of 80-110 GHz, one of the best CG and LO-RF isolation results ever reported for a down-conversion mixer with operation frequency around 94 GHz. Furthermore, the mixer achieves an excellent input third-order intercept point of −3 dBm at 94 GHz. These results demonstrate the proposed down-conversion mixer architecture is promising for 94 GHz image radar sensors. [ABSTRACT FROM AUTHOR]

A novel full D-band (110–170 GHz) multi-mode transconductance down-converter mixer is realized in a 250-nm indium–phosphide double heterojunction bipolar transistor technology. A single-balanced topology is chosen and an active power combiner for the RF and the local oscillator (LO) signals’ combination is used. The designed mixer is feasible to work at \, \times \,1, \, \times \,2, \, \times \,3, \, \times \,4 subharmonically LO-pumped mixing modes with relatively low LO powers of 0, -\1, 5, and 6 dBm, respectively. The measured conversion gain achieves typical values of -\3, -\1, -\5, and -\4 dB over the full D-band while the best noise figures of 12, 13.5, 18.5, and 19 dB are obtained, respectively. Through the multi-mode operation in terms of subharmonic LO-pump-frequency, the designer can make a tradeoff between LO frequency, LO power, and noise figure. [ABSTRACT FROM PUBLISHER]

A novel low-IF double balanced CMOS Gilbert mixer with high linearity and conversion gain is presented in this paper. An innovative easy-implemented cross-coupled full differential multiple gated transistor topology is proposed to improve the linearity while maintaining the high conversion gain. In addition, a topology, which artfully combines the current-bleeding technology and the noise-cancelling technology, is introduced to reduce the noise figure. The prototype of the proposed circuit was fabricated in SMIC 0.18 μm CMOS process with a chip area of 0.32 × 0.24 mm. The measurement results have exhibited an IIP3 of 10.2 dBm and a conversion gain of 17.8 dB with a power dissipation of 3.6 mW from 1.8 V supply. Compared to recently published studies, the proposed work has achieved a higher FoM. [ABSTRACT FROM AUTHOR]

Mobile devices demand low-power WiFi receivers for extended battery lifetime. This paper presents the design of an 11.6-mW receiver including baseband channel selection filtering that targets the IEEE802.11a standard. A 1-to-6 on-chip transformer serves as a low-noise amplifier with zero power dissipation and high linearity while providing ESD protection and differential outputs. The co-design of the transformer and the passive mixers leads to an efficient front end. Realized in 65-nm CMOS technology, the prototype exhibits a noise figure of 6 dB and a sensitivity of - 66 dBm at a data rate of 54 Mb/s from 5 GHz to 5.9 GHz. A new analysis of fully-differential current-driven passive mixers is also presented to facilitate the design of the front end. [ABSTRACT FROM AUTHOR]

ABSTRACT A 75-85 GHz double-balanced down-conversion mixer for automotive radars using standard 90 nm CMOS technology is reported. The down-conversion mixer comprises a double-balanced Gilbert cell with inductive source-degeneration RF transconductance stage for RF-port input matching bandwidth and conversion gain (CG) enhancement, a Marchand balun for converting the single RF input signal to differential signal, a Marchand balun for converting the single LO input signal to differential signal, and a baseband amplifier. The mixer consumes 13 mW and achieves excellent RF-port input reflection coefficient of −13.1 to −19.4 dB and LO-port input reflection coefficient of −9.1 to −11.8 dB for frequencies of 75-85 GHz. In addition, for frequencies of 75-85 GHz, the mixer achieves CG of −1 to 1.5 dB, LO-RF isolation of 43.5-49.2 dB, LO-IF isolation of 56.5-64.5 dB and RF-IF isolation of 35.9-39.4 dB, one of the best CG and port-to-port isolation results ever reported for a CMOS down-conversion mixer with operation frequency around 80 GHz. Furthermore, the mixer achieves an excellent input third-order intercept point of 2.7 dBm at 79 GHz. These results demonstrate the proposed down-conversion mixer architecture is promising for W-band transceivers. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:73-80, 2015 [ABSTRACT FROM AUTHOR]

A design of RF down-conversion Gilbert-Cell, with 65nm CMOS technology, at a supply voltage of 1.8V, with a new degenerating structure to improve linearity. This architecture opens the way to more integrated CMOS RF circuits and to achieve a good characteristics in terms of evaluating parameters of RF mixers with a very low power consumption (2.17mW). At 1.9GHz RF frequency; obtained results show a third order input intercept point (IIP3) equal to 11.6dBm, Noise Figure (NF) is 4.12dB, when conversion gain is 8.75dB. [ABSTRACT FROM AUTHOR]

We analyze the operation and performance of subsampled analog optical links. These links downconvert microwave signals by optically sampling at a rate much lower than the RF carrier frequency. Expressions for conversion gain, noise figure, and spurious-free dynamic range are derived for intensity modulation and direct detection. The impact of pulse width on link performance is revealed and quantified. Also, in order to characterize noise in a subsampled link, the influence of timing jitter in the periodic optical source is considered. Timing jitter and pulse width are found to be two important factors which limit the noise figure and dynamic range in subsampled links. [ABSTRACT FROM PUBLISHER]

A 94 GHz CMOS down-conversion mixer is reported. RF negative resistance compensation (NRC) technique, i.e., PMOS LC-oscillator-based RF transconductance (GM) stage load, is used to increase the output impedance and suppress the feedback capacitance C\mathrm{gd} of RF GM stage. As a result, conversion gain (CG), noise figure (NF) and LO-RF isolation of the mixer are enhanced. For frequencies of 80∼110 GHz, the mixer consumes 6.3 mW and achieves excellent RF-port input reflection coefficient (S11) of -8.7\!\sim\!-22\;\textdB and LO-port input reflection coefficient (S22) of -10.3\!\sim\!-19.4\;\textdB. In addition, the mixer achieves excellent CG of 4.1∼11.6 dB, NF of 15.8∼18.1 dB, and LO-RF isolation of 42.1∼54 dB for frequencies of 80∼110 GHz, one of the best CG, NF and LO-RF isolation results ever reported for a W-band CMOS down-conversion mixer. [ABSTRACT FROM PUBLISHER]