• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.5
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• pp.538-544
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• 2011

This paper presents a compact single balanced diode mixer fabricated using a 0.1 ${\mu}M$ GaAs p-HEMT commercial process for an E-band frequency up/down converter. This mixer includes a LO balun employing a Marchand balun with a good RF performance. In order to improve the port-to-port isolation, a high pass filter and a low pass filter are include in this mixer at the RF and IF ports, respectively. The fabricated mixer with a very compact size of 0.58 mm2(0.85 mm${\times}$0.68 mm) exhibits a conversion loss of 8～12 dB and an input P1dB of 1～5 dBm at the LO power of 10 dBm from 71～86 GHz.

• Journal of electromagnetic engineering and science
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• v.8 no.3
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• pp.91-95
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• 2008

This paper presents a direct-conversion I/Q up-mixer block, which supports $3{\sim}5$ GHz ultra-wideband(UWB) applications. It consists of a VI converter, a double-balanced mixer, a RF amplifier, and a differential-to-single signal converter. To achieve wideband characteristics over $3{\sim}5$ GHz frequency range, the double-balanced mixer adopts a shunt-peaking load. The proposed RF amplifier can suppress unwanted common-mode input signals with high linearity. The proposed direct-conversion I/Q up-mixer block is implemented using $0.18-{\mu}m$ CMOS technology. The measured results for three channels show a power gain of $-2{\sim}-9$ dB with a gain flatness of 1dB, a maximum output power level of $-7{\sim}-14.5$ dBm, and a output return loss of more than - 8.8 dB. The current consumption of the fabricated chip is 25.2 mA from a 1.8 V power supply.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.4
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• pp.599-609
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• 2000

In this paper, sub-harmonically pumped single balanced resistive mixers are presented . Frequency bandwidth is selected for a Ku-band, which is 11.75-12.25GHz for RF, 5.375∼5.625 GHz for LO, and 1 GHz for IF signals. A rat-race hybrid is designed for the accomplishment of single balanced type. A low pass filter (LPF) with photonic band gap(PBG) structure is used for good conversion loss and unwanted harmonics suppression. Two types of mixers are suggested, which are one with no gate bias for no DC power consumption and the other with the IF amplifier for conversion gain. When a LO signal with the power of 6 dBm at 5.5 GHz is injected, a conversion loss of 12.17dB and a conversion gain of 7.83 dB are obtained for each mixer. For the both mixers , LO to RF isolation of 20 dB and LO to IF isolation of 60dB are obtained. With the RF power of -30dBm to -3dBm, the mixer shows linear characteristics region of IF. this mixer can be applied for Ku-band and other microwave communication systems.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.6
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• pp.272-275
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• 2004

A balanced single side-band (SSB) mixer employing a sub-harmonic configuration is designed for up and down conversions in K-band. The designed mixer uses anti-parallel diode (APD) pairs to effectively eliminate even harmonics of the local oscillator (LO) spurious signal. To reduce the odd harmonics of LO at the RF port, we employ a balanced configuration for LO. The fabricated chip shows 12$\pm$2dB of conversion loss and image-rejection ratio of about 20dB for down conversion at RF frequencies of 24-27.5GHz. As an up-conversion mode, the designed chip shows 12dB of conversion loss and image-rejection ratio of 20 ～ 25 dB at RF frequencies of 25 to 27GHz. The odd harmonics of the LO are measured below -37dBc.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.12
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• pp.1335-1340
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• 2003

In this paper, a single balanced diode Mixer for the homodyne FMCW radar to detect distance and velocity of a vehicle target is designed and implemented using a microstrip line and two schottky barrier beam lead diodes. This mixer is optimally designed to have less a conversion loss within the 100 MHz bandwidth with a little LO injection power and a higher LO isolation as soon as possible through the embedded electrical length of microsrtrip line placed between the coupler and diode matching, considering together LO matching condition. The measured results show 6 dB of conversion loss, 23 dB LO/RF isolation and 3 dBm of input 1l dB, respectively.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.857-860
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• 2005

We reported 94 GHz, low conversion loss, and high isolation single balanced active-gate mixer based on 70 nm gate length InGaAs/InAlAs metamorphic high electron mobility transistors (MHEMTs). This mixer showed that the conversion loss and isolation characteristics were 2.5 ${\sim}$ 2.8 dB and under -30 dB, respectively, in the range of 93.65 ${\sim}$ 94.25 GHz. The low conversion loss of the mixer is mainly attributed to the high-performance of the MHEMTs exhibiting a maximum drain current density of 607 mA/mm, a extrinsic transconductance of 1015 mS/mm, a current gain cutoff frequency ($f_t$) of 330 GHz, and a maximum oscillation frequency ($f_{max}$) of 425 GHz. High isolation characteristics are due to hybrid ring coupler which adopted dielectric-supported air-gapped microstrip line (DAML) structure using surface micromachined technology. To our knowledge, these results are the best performance demonstrated from 94 GHz single balanced mixer utilizing GaAs-based HEMTs in terms of conversion loss as well as isolation characteristics.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.426-429
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• 1988

A simple design method of a single balanced MMIC mixer is described. It uses small signal S11 and capacitive load for the input matching circuit and the output loading circuit, respectively. It is found that the conversion gain of the FET mixer is independent of FET gate width. The fabricated mixer has 2.5 dB conversion gain at 9 GHz with 50 ohm IF load and 2 dBm local oscillator power.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.4 s.346
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• pp.8-15
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• 2006

In this paper, the 94 GHz, low conversion loss, and high isolation single balanced mixer is designed and fabricated using GaAs-based metamorphic high electron mobility transistors (MHEMTs) with 70 nm gate length and the hybrid ring coupler with the micromachined transmission lines, dielectric-supported air-gapped microstrip lines (DAMLs). The 70 nm MHEMT devices exhibit DC characteristics with a drain current density of 607 mA/mm an extrinsic transconductance of 1015 mS/mm. The current gain cutoff frequency ($f_T$) and maximum oscillation frequency ($f_{max}$) are 320 GHz and 430 GHz, respectively. The fabricated hybrid ring coupler shows wideband characteristics of the coupling loss of $3.57{\pm}0.22dB$ and the transmission loss of $3.80{\pm}0.08dB$ in the measured frequency range of 85 GHz to 105 GHz. This mixer shows that the conversion loss and isolation characteristics are $2.5dB{\sim}>2.8dB$ and under -30 dB, respectively, in the range of $93.65GHz{\sim}94.25GHz$. At the center frequency of 94 GHz, this mixer shows the minimum conversion loss of 2.5 dB at a LO power of 6 dBm To our knowledge, these results are the best performances demonstrated from 94 GHz single balanced mixer utilizing GaAs-based HEMTs in terms of conversion loss as well as isolation characteristics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.6
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• pp.1269-1276
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• 2005

In this paper, Mixer using the direct-conversion method intended to use in front-end of a RF receiver is designed. The direct conversion Mixer is an alternative wireless receiver architecture to the well-established superheterodyne, particularly for high integration, low power, and low cost. It operates at 2.4GHz band, and is designed and simulated with a 0.35um CMOS technology and HSPICE simulator. Layout is implemented with a Mentor IC Station. The 2.4GHz CMOS Mixer employs a modified single-balanced Gilbert Cell with additional MOSFET in the output stages to improve IIP2, which is a standard of linearity in direct conversion receiver. Additional coversion-stages's transconductances are controlled by each MOSFET's physical properties. The HSPICE simulation results show that the 2.4GHz CMOS Mixer has voltage gam of 29dB, IIP2 of 63dBm, respectively. The Mixer also draws 3.5mA from a 3.3V supply.

• International journal of advanced smart convergence
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• v.10 no.3
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• pp.81-88
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• 2021

This paper proposes two types of subharmonic RF receiver front-end (called LMV) where, in a single stage, quadrature voltage-controlled oscillator (QVCO) is stacked on top of a low noise amplifier. Since the QVCO itself plays the role of the single-balanced subharmonic mixer with the dc current reuse technique by stacking, the proposed topology can remove the RF mixer component in the RF front-end and thus reduce the chip size and the power consumption. Another advantage of the proposed topologies is that many challenges of the direct conversion receiver can be easily evaded with the subharmonic mixing in the QVCO itself. The intermediate frequency signal can be directly extracted at the center taps of the two inductors of the QVCO. Using a 65 nm complementary metal oxide semiconductor (CMOS) technology, the proposed subharmonic RF front-ends are designed. Oscillating at around 2.4 GHz band, the proposed subharmonic LMVs are compared in terms of phase noise, voltage conversion gain and double sideband noise figure. The subharmonic LMVs consume about 330 ㎼ dc power from a 1-V supply.