• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.3
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• pp.381-389
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• 2015

A fully integrated multistandard multiband CMOS mobile TV tuner with small silicon area and low power consumption is proposed for receiving multiple mobile digital TV signals and FM signal. In order to reduce the silicon area of the multistandard multiband receiver, other RF front-end circuits except LNAs are shared and a local oscillator (LO) signal generation architecture with a single VCO for a frequency synthesizer is proposed. To reduce the low frequency noise and the power consumption, a vertical NPN BJT is used in an analog baseband circuits. The RF tuner IC is implemented in a $0.18-{\mu}m$ CMOS technology. The RF tuner IC satisfies all specifications for DVB-H/T, T-DMB, and ISDB-T with a sufficient margin and a successful demonstration has been carried out for DVB-H/T, T-DMB, and ISDB-T with a digital demodulator.

• Journal of IKEEE
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• v.15 no.4
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• pp.281-286
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• 2011

DVB-T2 is a next generation DTV transmission standard, which supports various channel bandwidths. Since the symbol rate of the DVB-T2 signal is changed according to its bandwidth, the received signal needs to be sampled at a different frequency. The sampling frequency should be also adjusted depending on the sampling frequency offset due to the frequency error in the local oscillator. The sampling frequency can be locked into the symbol frequency by resampling the sampled data by ADC running at a fixed frequency. In this paper a resampler architecture for DVB-T2 is proposed. And the simulation results reveal the spectral characteristics of each subcarriers used in DVB-T2 system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.507-511
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• 2010

Digital Radio Frequency Memory (below, DRFM) performs RF signal data store, delay and re-transmission. DRFM is wildly used as core module of Jammer, EW simulator, Target Echo Generator etc. This paper suggests a hardware design of DRFM which is composed RF section(RF Input/Output Module, Local Oscillator Module) and Digital section(ADC module, memory, DAC module), and confirm the validity of the propose by the test result.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.195-200
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• 2018

A W-band frequency octupler is implemented on 100-nm GaAs pHEMT process. The fabricated octupler can be used as a local oscillator or a signal source of W-band transceivers. Three common-source doublers are connected in cascade to multiply an input signal of 10.75 GHz to 83 GHz. A common-source amplifier is followed for each doubler to improve the conversion gain and suppress the unwanted harmonics. The fabricated octupler showes high output of more than 6 dBm in the 80 - 84 GHz band and achieved excellent spurious suppression performance over 20 dBc.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.9
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• pp.1010-1019
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• 2008

In this paper, we present a noise analysis and measurement results of a bio-radar system that can detect human heartbeat and respiration signals. The noise analysis including various phase noise effects is very important in designing the bio-radar system, since the frequency difference between the received signal and local oscillator is very small and the received power is very low. All of the noise components in a bio-radar system are considered from the point of view of SNR. From this analysis, it can be concluded that the phase noise due to antenna leakage is a dominant factor and is a function of range correlation. Therefore, the phase noise component with range correlation effect, which is the most important noise contribution, is measured using the measurement setup and compared with the calculated results. From the measurement results, our measurement setup can measure a closed-in phase noise of a free-running oscillator. Based on these results, it is possible to design a 2.4 GHz bio-radar system quantitatively which has a detection range of 50 cm and low power of 1 mW without additional PLL circuits.

• ETRI Journal
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• v.26 no.3
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• pp.229-240
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• 2004

This paper reports on our development of a dual-mode transceiver for a CMOS high-rate Bluetooth system-onchip solution. The transceiver includes most of the radio building blocks such as an active complex filter, a Gaussian frequency shift keying (GFSK) demodulator, a variable gain amplifier (VGA), a dc offset cancellation circuit, a quadrature local oscillator (LO) generator, and an RF front-end. It is designed for both the normal-rate Bluetooth with an instantaneous bit rate of 1 Mb/s and the high-rate Bluetooth of up to 12 Mb/s. The receiver employs a dualconversion combined with a baseband dual-path architecture for resolving many problems such as flicker noise, dc offset, and power consumption of the dual-mode system. The transceiver requires none of the external image-rejection and intermediate frequency (IF) channel filters by using an LO of 1.6 GHz and the fifth order onchip filters. The chip is fabricated on a $6.5-mm^{2}$ die using a standard $0.25-{\mu}m$ CMOS technology. Experimental results show an in-band image-rejection ratio of 40 dB, an IIP3 of -5 dBm, and a sensitivity of -77 dBm for the Bluetooth mode when the losses from the external components are compensated. It consumes 42 mA in receive ${\pi}/4-diffrential$ quadrature phase-shift keying $({\pi}/4-DQPSK)$ mode of 8 Mb/s, 35 mA in receive GFSK mode of 1 Mb/s, and 32 mA in transmit mode from a 2.5-V supply. These results indicate that the architecture and circuits are adaptable to the implementation of a low-cost, multi-mode, high-speed wireless personal area network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.7
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• pp.944-950
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• 1993

Diodes and GaAs have been commonly used in a mixer design until recently. However, diodes are not preferred to use at the front-end of DBS receiver due to the conversion loss large noise. HEMT has larger conversion gain and better noise characteristics comparing with GaAs MESFET. This paper describes the design procedure, structure, and performance of a mixer, utilizaing HEMT designed by OKI Co. . A mixer configuration in which the local oscillator(LO) signal is applied to the gate is used. When the LO power is 0.01 dBm, the conversion gain of 3.7dB is obtained at IF and the 3 dB bandwidth is 400MMz.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.2
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• pp.111-116
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• 2003

In this paper, a CMOS baseband analog receiver for wireless home network is discussed. It is composed of a Gilbert type mixer, an Elliptic 6th order 1ow pass filter, and a 6-bit A/D converter. The main role of the mixer is generating a mixed analog signal between the 200MHz output signal of CMOS RF stage and the 199MHz local oscillator. After the undesired high frequency component of the mixed signal comes out. Finally, the analog signal is converted into digital code at the 6-bit A/D converter, The proposed receiver is fabricated with 0.25${\mu}{\textrm}{m}$ 1-poly 5-metal CMOS technology, and the chip area is 200${\mu}{\textrm}{m}$ X1400${\mu}{\textrm}{m}$. the receiver consumes 130㎽ at 2.5V power supply.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.8
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• pp.737-743
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• 2004

A fixed-tuned SIS(Superconductor-Insulator-Superconductor) mixer across 120∼180 GHz band has been developed. This mixer employs an SIS chip fabricated by Nobeyama radio observatory which consists of a series array of 6 Nb/Al-Al$_2$O$_3$/Nb junctions in a microstrip line on a fused quartz substrate. The SIS chip is placed at the center of the half-height waveguide mixer mount to have a good incoming signal coupling over the whole frequency band. No mechanical tuner was used in the SIS mixer and the RF signal and local oscillator power are injected to the mixer via a cooled cross-guide coupler. In order to prevent the IF signal loss, the If output impedance of the SIS mixer was matched to the 50 $\Omega$ input impedance of the IF chain. Measured double sideband noise temperatures of a receiver using the SIS mixer are 32∼131 K over 120∼180 GHz band. The developed SIS mixer is now in use for radio astronomical observations on the TRAO 14 m radio telescope.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.4
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• pp.442-450
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• 2008

In this paper, the phase diverisity in a direct-conversion receiver for a UHF RFID reader is analyzed and the optimal I/Q signal combining methods is presented with respect to tag modulation. At first, fading characteristics of a single channel receiver is shown to prove the importance of phase diversity due to the phase relationship between the backscattered signal and the local oscillator. And the optimal signal combining methods are presented in order to overcome the signal power reduction due to phase diversity. In case of ASK, the power combining method is presented for the optimal I/Q combining. And the arctangent and principal component combining methods using covariance matrix of I and Q channels are presented for the optimal I/Q combining in case of PSK. In order to analyze the performance of suggested methods, the selection diversity and the optimal combining methods are compared. According to analysis and simulation results, the optimal combining methods have a maximum 3 dB SNR enhancement than selection diversity.