• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.86-89
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• 2003

In this paper, Self-Oscillating Mixer is designed by oscillator that was based on a general nonlinear input-output model for the subharmonic injection locked oscillator is analysed. We have designed and fabricated the Self-Oscillating Mixer for 5GHz by proposed subharmonic injection locked oscillator based frequency synthesizer structure that have characteristic of good frequency sensitivity, good phase noise. The design strategy leading to an optimized SILO with regards to its locking range is described and a test SOM circuit is demonstrated a 4dB conversion gain at 280MHz IF frequency from the carrier.

• Journal of electromagnetic engineering and science
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• v.8 no.1
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• pp.34-39
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• 2008

An RF front-end dual-conversion receiver for $3{\sim}5\;GHz$ MB-OFDM UWB systems is implemented in $0.18\;{\mu}m$ CMOS technology. The receiver includes a two-stage UWB LNA, an RF mixer, an IF I/Q mixer, and a frequency synthesizer. The proposed receiver adopts the dual-conversion architecture to mitigate the burden of design of the frequency synthesizer. Accordingly, the proposed frequency synthesizer generates four LO tones from only one VCO. The receiver front-end achieves power gain of 16.3 to 21 dB, NF of 7 to 7.6 dB over $3{\sim}5\;GHz$, and IIP3 of -21 dBm, while consuming 190 mW from a 1.8 V supply.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.3
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• pp.413-419
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• 1987

In this paper, self-oscillating mixer is designed by small signal S-parameter and series feedback circuit. The input-output matching circuit is accomplished from double stub and additional matching stub. The self-oscillating mixer is oscillating itself and amplifies without any external local oscillator and an intermediate frequency amplifier, so it has advantages in its economical and system simplification. The experimental results show the maximum conversion gain 1.5d B and the noise figure 6.5d B at RF center frequency 4GHz and IF 1.1GHz` output oscillating power 4d Bm, efficiency 13.4%, stability -10MHz/V and -0.5MHz/\ulcornerC at oscillating frequency 5.1GHz.The rejection band loss characteristics in band pass filter and low pass filter are -40d B and -30d B, respectively.

• 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.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.5
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• pp.1-10
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• 1998

A GaAs MMIC composed of VCO (voltage controlled oscillator) and mixer for PCS receiver has been developed using 1.mu.m ion implanted GaAs MESFET process. The VCO consists of a colpitts-type oscillator with a dielectric resonator and the circuit configuration of the mixer is a dual-gate type with an asymmetric combination of LO and RF FETs for the improvement of intermodulation characteristics. The common-source self-biasing is used in all circuits including a buffer amplifier and mixer, achieving a single power supply (3V) operation. The total power dissipation is 78mW. The VCO chip shows a phase noise of-99 dBc/Hz at 100KHz offset. The combined VCO/mixer chip shows a flat conversion gain of 2dB, the frequency-tuning factor of 80MHz/volts in the varacter bias ranging from 0.5V to 0.5V , and output IP3 of dBm at varactor bias of 0V. The fabricated chip size is 2.5mm X 1.4mm.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.921-924
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• 2005

We report low conversion loss and high LO to RF isolation 94 GHz MMIC resistive mixers based on 0.1 ${\mu}m$ InGaAs/InAlAs/GaAs metamorphic HEMT technology. The fabricated resistive mixers applied a one-stage amplifier on RF port of the mixer. By using the one-stage amplifier, we obtained the decrement of conversion loss and the increment of LO to RF isolation. So, we can obtain higher performances than conventional resistive mixers. The modified mixer shows excellent conversion loss of 6.7 dB at a LO power of 10 dBm. We also observed an extremely high isolation characteristic from the MMICs exhibiting the LO-RF isolation of 21 ${\pm}$ 0.5dB in a frequency range of 93.7${\sim}$ 94.3 GHz. The low conversion loss and high LO-RF isolation characteristics of the MMIC modified resistive mixers are mainly attributed to the performance of the MHEMTs exhibiting a maximum transconductance of 654 mS/mm, a current gain cut-off frequency of 173 GHz and a maximum oscillation frequency of 271 GHz.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.7 no.2
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• pp.71-77
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• 1982

This poper proposes the method of the balanced-mixer realization in the X-Band frequency range by the MIC coplanar magic-tee. This magic-tee is composed with microstrip and slot, as suggested by Ronde. The characteristics of balancing and isolation in this magic-tee is more preferable to those of the rat-race or hybrid ring in the wide frequency range. So, experimentally in this paper the characteristics of the MIC balanced-mixed are obtained with the VSWR less than 1, 2(in Local and Signal Arms) and the Conversion Loss, 6 dB in that frequency range, when the mixer is designed in the 3rd order (in E-arm) and 2nd order(in H-arm) Chebyshev matching networks, and with two symmetrical Schottkey Barrier Diodes.

• ETRI Journal
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• v.27 no.5
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• pp.569-578
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• 2005

The purpose of this paper is to describe the implementation of monolithically matching circuits, interface circuits, and RF core circuits to the same substrate. We designed and fabricated on-chip 1 to 6 GHz up-conversion and 1 to 8 GHz down-conversion mixers using a 0.8 mm SiGe hetero-junction bipolar transistor (HBT) process technology. To fabricate a SiGe HBT, we used a reduced pressure chemical vapor deposition (RPCVD) system to grow a base epitaxial layer, and we adopted local oxidation of silicon (LOCOS) isolation to separate the device terminals. An up-conversion mixer was implemented on-chip using an intermediate frequency (IF) matching circuit, local oscillator (LO)/radio frequency (RF) wideband matching circuits, LO/IF input balun circuits, and an RF output balun circuit. The measured results of the fabricated up-conversion mixer show a positive power conversion gain from 1 to 6 GHz and a bandwidth of about 4.5 GHz. Also, the down-conversion mixer was implemented on-chip using LO/RF wideband matching circuits, LO/RF input balun circuits, and an IF output balun circuit. The measured results of the fabricated down-conversion mixer show a positive power conversion gain from 1 to 8 GHz and a bandwidth of about 4.5 GHz.

• Journal of electromagnetic engineering and science
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• v.2 no.2
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• pp.117-123
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• 2002

This paper describes the design for the resistive FET mixer with low If for the 4-Ch DBF(Digital Beam Forming) receiver This DBF receiver based on the direct conversion method is generally suitable for high-speed wireless mobile communications. A radio frequency(RF), a local oscillator(LO) and an intermediate frequency(If) considered in this research are 2.09 GHz, 2.08 CHz and 10 MHz, respectively. This mixer is composed of band pass filter, a low pass filter and a DC bias circuit. Super low noise HJ FET of NE3210S01 is considered in design. The RE input power, LO input power and Vcs are used -10 dBm, 6 dBm and -0.4 V, respectively. In the 4-Ch resistive FET mixer, the measured If and harmonic components of 10 MHe, 20 MHz and 2.087 CHz are about -19.2 dBm, -66 dBm and -48 dBm, respectively The If output power observed at each channel of 10 MHz is about -19.2 dBm and it is higher 28.8 dBm than the maximum harmonic component of 2.087 CHz. Each If output spectrum of the 4-Ch is observed almost same value and it shows a good agreement with the prediction.

• 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.