• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.127-132
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• 2013

In this paper, we design the physical layer of Guardian modem for wireless public networks. The physical layer is composed of a dual-band RF (Radio Frequency) transceiver and a baseband-processor with quasi-orthogonal codes. The 2.4/5GHz dual-band RF transceiver can overcome the communication difficulty of dense 2.4GHz band for wireless public environment. Also the quasi-orthogonal code can reduce the required ASIC (Application Specific Integrated Circuit) design area. Finally, we analyze the performance of the developed system in viewpoint of data rate, BER (Bit Error Rate), PER (Packet Error Rate). Moreover we verify the performance of the dual-band RF communication.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.2
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• pp.147-155
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• 2002

This paper describes RF front-end transceiver chipset for the dual-mode operation of PCS-Korea and IMT-2000. The transceiver chipset has been implemented in a $0.25\mutextrm{m}$ single-poly five-metal CMOS technology. The receiver IC consists of a LNA and a down-mixer, and the transmitter IC integrates an up-mixer. Measurements show that the transceiver chipset covers the wide RF range from 1.8GHz for PCS-Korea to 2.1GHz for IMT-2000. The LNA has 2.8~3.1dB NF, 14~13dB gain and 5~4dBm IIP3. The down mixer has 15.5~16.0dB NF, 15~13dB power conversion gain and 2~0dBm IIP3. The up mixer has 0~2dB power conversion gain and 6~3dBm OIP3. With a single 3.0V power supply, the LNA, down-mixer, and up-mixer consume 6mA, 30mA, and 25mA, respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.2
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• pp.27-32
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• 2018

In this paper, W-band transceiver module for compact radar has been designed and fabricated. Utilizing proposed microstrip-to-waveguide transition, the error between design and implementation is reduced. The proposed transition provides less than 1 dB insertion loss per transition and reliability for fabrication. In order to apply compact radar with dual-polarized monopulse directly, W-band transmitter with 28 dBm output power is designed and developed. Also, 6 channels of receiver module with low noise figure 13.5 dB and maximum 17 dBm input P1dB is developed. Proposed W-band transceiver module is expected compact radar application for dual-polarized monopulse signal processing system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.233-237
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• 2017

The dual-channel receiver MMIC which is composed of LNA, Mixer, LO-amp and temperature compensation circuit is designed on a single chip. For the performance comparison, a FMCW radar transceiver module using commercial MMICs is also implemented. As a result, Multi-channel Transceiver using manufactured MMIC shows an improved performance such as noise figure and gain flatness compare to purchased MMIC.

• 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.35 no.5A
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• pp.496-503
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• 2010

The implementation of a RF transceiver for WRAN(Wireless Regional Area Network) system based on IEEE 802.22 standard using Cognitive Radio technology is presented in this paper. A CMOS RF transceiver IC for WRAN system operates in VHF/UHF(54~862MHz) broadband, and employs dual-path direct-conversion configuration and the in-band harmonic distortions are effectively suppressed by exploiting the dual-path direct conversion architecture. For 64QAM(3/4 coding rate) OFDM signal, an EVM of <-31.4dB(2.7%) has been achieved at 10dBm off-chip PA output power and the total chip area with pads is 12.95 mm2. The experimental results show that the proposed CMOS RF transceiver IC has perfect performance for WRAN system based on TDD(Time Division Duplex) mode.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.3
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• pp.376-379
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• 2014

In this paper, we designed more improving a dual-band power amplifier than the transceiver of RFID reader that operates at 910 MHz and 2.45 GHz. A dual-band power amplifier has two circuits. One matching circuit is composed lumped element in the band of 910 MHz. The other matching circuit using distributed element in the high band of 2.45 GHz. So, this dual-band power amplifier works as Band Rejection Filter in the band of 910 MHz but in the high band of 2.45 GHz works as Band Pass Filter. Therefore, this is composed a microstrip transmission line. A power amplifier is showed gains of 8 dB output power at 910 MHz and 1.5 dB output power at 2.45 GHz. If input power is 10 dBm, both of bands output 20 dBm.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.1
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• pp.24-29
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• 2009

In this paper, we show the implementation of the low-cost RF transceiver module for parking control system. Super regenerative receiver scheme was adopted for this module due to its simplicity, low-cost, low power consumption and small number of components to improve reliability of the systems. For improving communication error rate by collision and in-band noise, dual-channel hopping scheme was adopted. Testing prototypes under the environment of simultaneous transmissions, we verified that the designed scheme is able to improve the success rate of data transmission of wireless parking control system cost effectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.12
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• pp.1712-1718
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• 2013

This paper proposes a compact dual-band 3-way power divider that helps lowering the weight of a transceiver for the L-band or multi-purpose satellite communication. Instead of the multi stages or tapering which ends up with loss accumulation and size-growth, the non-linear dispersive phases from the metamaterial CRLH(composite right and left-handed) properties are obtained by the accurate formulation and implemented by the short transmission line segments. Firstly, the CRLH dual-band two-way unequal power divider and equal power divider are separately designed. And then, the input of the two-way equal power divider is plugged in the output port of the unequal one, and the entire geometry is slightly adjusted for the desirable performance. The circuit analysis and full-wave simulation are used to predict the frequency responses and validated by the measurement of the prototype. Besides, the size-reduction effect is addressed.

• Journal of IKEEE
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• v.16 no.1
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• pp.62-68
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• 2012

The planar microstrip antenna for the safety communication of life at sea is designed and manufactured to effectively receive the emergency wireless signal from the transmitter on the life vest. The proposed microstrip antenna in this paper is easy to make, light weight and cheap compared to other antennas because of printed antenna fabrication. To overcome the narrow bandwidth, large size and low gain characteristics of microstrip antenna, we use the IDMA(Identical Dual Patch Microstrip Antenna with Air-Gap) structure. The proposed antenna was fabricated with the use of 1.6mm FR4 and measured with the 28.7MHz(6.6%) of bandwidth and 3.04dBi of gain at the frequency of 426MHz. To validate the proposed antenna, we experimented the possible distance range at sea using the commercial UHF transceiver module and obtained over 5km distance for stable communication. This antenna can be widely applied to application of the UHF wireless mobile communication.