• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.12
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• pp.1350-1359
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• 2008

This paper presents a wideband doubly balanced resistive mixer fabricated using $0.5{\mu}m$ GaAs p-HEMT process. Three baluns are employed in the mixer. LO and RF baluns operating over an 8 to 20 GHz range were implemented with Marchand baluns. In order to reduce chip size, the Marchand baluns were realized by the meandering multicoupled line and inductor lines were inserted to compensate for the meandering effect. IF balun was implemented through a DC-coupled differential amplifier. The size of IF balun is $0.3{\times}0.5\;mm^2$ and the measured amplitude and phase unbalances were less than 1 dB and $5^{\circ}$, respectively from DC to 7 GHz. The mixer is $1.7{\times}1.8\;mm^2$ in size, has a conversion loss of 5 to 11 dB, and an output third order intercept(OIP3) of +10 to +15 dBm at 16 dBm LO power for the operating bandwidth.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.4
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• pp.403-409
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• 2013

In this work, a CMOS two stage differential power amplifier which includes Marchand balun, transformer and injection-locked buffer is presented. The power amplifier is targeted for 70 GHz frequency band and fabricated using 65 nm technology. The measurement results show 8.5 dB maximum voltage gain at 71.3 GHz and 7.3 GHz 3 dB bandwidth. The measured maximum output power is 8.2 dBm, input $P_{1dB}$ is -2.8 dBm, output $P_{1dB}$ is 4.6 dBm and maximum power added efficiency is 4.9 %. The power amplifier consumes 102 mW DC power from 1.2 V supply voltage.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.10
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• pp.1166-1174
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• 2008

In this paper, design of a $2{\sim}18$ GHz wideband cavity-backed spiral antenna is investigated. Firstly, an arm pattern and a backing cavity of a cavity-backed spiral antenna are designed based on the design theory of an Archimedean spiral antenna as well as by using CST's MWS. VSWR, axial ratio, and HPBW(Half Power Beam Width) characteristics are considered in the simulation. Secondly, a Marchand coaxial balun is designed to meet the required VSWR within the frequency band of operation. Finally, the validity of these approaches is verified by comparing the simulated results with measured ones.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.44-50
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• 2004

In this paper, a DBM(Doubly Balanced Mixer) of 2 GHz is implemented on FR4 substrate. The structure of doubly balanced mixer requires, in general, two batons and a quad diode. For balun, a novel planar balun using microstrip to CPS is suggested and designed. The suggested balun shows the phase imbalance of 180$^{\circ}$${\pm}$ 1.5$^{\circ}$and the amplitude imbalance of ${\pm}$ 0.2 ㏈ for 1.5 to 2.5 GHz. Using the balun, DBM is succesfully implemented, and the measured conversion loss of up/down converter show about 6 ㏈ over the bandwidth. The balun may be applicable for MMIC DBM with the process supporting backside via thourgh more study.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.2 no.1
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• pp.22-29
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• 2003

A circuit model for the transition of stripline to dual slotline and a segmented method to analyze a notch antenna are presented. For the circuit model of the transition, the characteristic impedance, dispersions, and the shorted impedance of dual slotline are calculated and approximated with the closed-form expressions. The segmented analysis method allows to get readily an optimized results for the dual slotline-fed notch antenna. As a design example, a notch antenna is segmented into a 4'h order Marchand balun and a dual slot 134 notch antenna, and tested to show the validity of the proposed circuit model.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2321-2323
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• 2005

본 논문에서는 지수형으로 테이퍼 된 슬롯 안테나로 광대역 안테나를 설계하였다. 이 안테나는 VSWR${\leq}2$를 기준으로 $6GHz{\sim}18GHz$까지 3:1의 광대역 특성을 나타낸다. 급전부는 마이크로스트립으로 설계되었고 안테나는 싱글 슬롯으로 설계하였기 때문에 급전부와 안테나 사이의 트랜지션은 marchand balun을 이용하여 해결하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10A
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• pp.847-851
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• 2011

In this paper, we reported on a high performance MMIC star mixer for millimeter-wave applications. The star mixer was fabricated using drain-source-connected pseudomorphic high electron mobility transistor (PHEMT) diodes considering the PHEMT MMIC full process on 2 mil thick GaAs substrate. The average conversion loss of 13 dB was measured in the RF frequency range of 81 GHz to 86 GHz at LO frequency of 75 GHz with LO power of 10 dBm. The RF-LO isolation characteristics are greater than 30 dB and the input 1-dB compression are approximately 4 dBm. The total chip size is 0.8 mm ${\times}$ 0.8 mm.