[1] Duan Jihai, Wang Zhigong, Li Zhiqun, et al. A modulator using RF CMOS T-type attenuatorfor TH-UWB communications [J]. Journal of Southeast University (English Edition), 2009, 25 (4): 435-438. [doi:10.3969/j.issn.1003-7985.2009.04.004]

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A modulator using RF CMOS T-type attenuatorfor TH-UWB communications()

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Journal of Southeast University (English Edition)[ISSN:1003-7985/CN:32-1325/N]

Volumn:

25

Issue:

2009 4

Page:

435-438

Research Field:

Circuit and System

Publishing date:

2009-12-30

Info

Title:

A modulator using RF CMOS T-type attenuatorfor TH-UWB communications

Author(s):

Duan Jihai¹;  2;  Wang Zhigong¹;  3;  Li Zhiqun¹;  3

¹School of Integrated Circuits, Southeast University, Nanjing 210096, China
² School of Information and Communication, Guilin University of Electronic Technology, Guilin 541004, China
³Institute of RF- & OE-ICs, Southeast University, Nanjing 210096, China

Keywords:

attenuator;  insertion loss(IL);  on-off keying(OOK);  RF CMOS

PACS:

TN402

DOI:

10.3969/j.issn.1003-7985.2009.04.004

Abstract:

The insertion loss(IL)of a T-type attenuator is theoretically analyzed. A T-type RF(radio frequency)CMOS(complementary metal-oxide-semiconductor)attenuator is designed as an on-off keying(OOK)modulator in a time-hopping ultra wide-band(TH-UWB)communication with a carrier frequency of 4 GHz. In the topology of the OOK modulator circuit, there are three parts, an oscillator with an oscillating frequency of 4 GHz, a T-type attenuator constructed by RF CMOS transistors, and an output impedance matching network with a L-type LC structure. The modulator is controlled by a time-hopping pulse position modulation(TH-PPM)signal. The envelope of the modulated signal varies with the amplitude of the controlling signal. Meanwhile, an output matching network is also designed to match a 50 Ω load. In 0.18 μm RF CMOS technology, a modulator is designed and simulated. The implemented modulator chip has 65 mV of the output amplitude at a 50 Ω load from a 1.8 V supply, and the return loss(S₁₁)at the output port is less than -10 dB. The chip size is 0.7 mm×0.8 mm, and the power consumption is 12.3 mW.

References:

[1] Win Moe Z. Spectral density of random UWB signals [J]. IEEE Communications Letters, 2002, 6(12): 526-528.
[2] Win Moe Z, Scholtz Robert A. Ultra-wide bandwidth signal propagation for indoor wireless communications [C]//Proceedings of IEEE International Conference on Communications. Montreal, Canada, 1997: 56-60.
[3] Laney David C, Maggio Gian Mario. Multiple access for UWB impulse radio with pseudochaotic time hopping [J]. IEEE Journal on Selected Areas in Communications, 2002, 20(9): 1692-1700.
[4] Dogan H, Meyer R G, Niknejad A M. A DC-2.5 GHz wide dynamic-rang attenuator in 0.13 μm CMOS technology [C]//Proceedings of VLSI Circuits Symp Dig. Kyoto, Japan, 2005: 90-93.
[5] Dogan H, Meyer R G, Niknejad A M. Intermodulation distortion in CMOS attenuator and switches [J]. IEEE J Solid-State Circuits, 2007, 42(3): 529-539.
[6] Dogan H, Meyer R G, Niknejad A M. A DC-10 GHz linear-in-dB attenuator in 0.13 μm CMOS technology [C]//Proceedings of IEEE Custom Integrated Circuits Conf. Orlando, Fl, USA, 2004: 609-612.
[7] Dogan H, Meyer R G, Niknejad A M. Analysis and design of RF CMOS attenuators [J]. IEEE J Solid-State Circuits, 2008, 43(10): 2269-2283.

Memo

Memo:

Biographies: Duan Jihai(1964—), male, graduate, associate professor;Wang Zhigong(corresponding author), male, doctor, professor, zgwang@seu.edu.cn.
Citation: Duan Jihai, Wang Zhigong, Li Zhiqun. A modulator using RF CMOS T-type attenuator for TH-UWB communications[J]. Journal of Southeast University(English Edition), 2009, 25(4): 435-438.

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