Wai Wa CHOI, Welsy  蔡偉華
Associate Professor
GE Course Area Coordinator (Physical Science and the World) in CTLE

Academic Qualifications | Research Sojourn | Academic and Professional Working Experiences | Student Honors and Awards under Advisory | Professional Affiliations | University Teaching and Student Supervision | Research | Publications | Applied Research Achievements and Creative Works | Service to the University and the Wider Community | Contact Details

Academic Qualifications
Research Sojourn
Academic and Professional Working Experiences
Student Honors and Awards under Advisory
Professional Affiliations
University Teaching and Student Supervision

Teaching of Undergraduate (UG) and Postgraduate (PG) Courses

Postgraduate Student Supervisions

From 2009 till now, 3 master students were graduated under his supervision. Among of them, 1 master graduate was awarded best student paper prize in an international conference.

BSc Final Year Project Supervisions

Dr. Choi has supervised and co-supervised 7 BSc graduate designs and 3 of them were awarded the honors of “FST Dean List” in 2012 – 2014.

Curriculum Development and General Education Teaching

From 2009 to 2011, Dr. Choi has joined the GE Course Development Team of Physical Science and The World Area (Area 6) as a member and contributed to the course development. The area courses aim to prepare the undergraduate students will not only acquire academic knowledge but also be stimulated to think about the relationship between science, human society and their impact to the modern society development. Since 2012, Dr. Choi has been nominated as the GE Course Area Coordinator of Area 6 (Physical Science and the World) by the Centre for Teaching and Learning Enhancement to University so as to support the management of all 4 courses in Area 6.


Research

Research Interests

Dr. Choi’s research highlight is about tunable microwave filter and UWB (Ultra-Wide Band) differential filter that are important front-end component for modern compact multi-functional portable devices.

External Research Grant (PI)

Internal Research Grant (PI)


Publications

In the period under review from 2009 to 2014, 2 research projects had been completed; 11 international journal papers and 15 conference papers had been published. According to the Journal Citation Reports (JCR), 9 of 11 journal papers were published in Q1 rank including prestigious IEEE periodicals like IEEE Transactions on Microwave Theory and Techniques; IEEE Microwave and Wireless Components Letters; IEEE Transactions on Antennas and Propagation and IEEE Antennas and Wireless Propagation Letters. 4 conference papers were published in Top 3 International Conferences of the field including IEEE International Microwave Symposium; European Microwave Conference and Asia Pacific Microwave Conference. The citation index is 139 for all my publications since 2009 while the total citation is 163 with h-index as 6.

Summary of Journal Papers in Review Period 2009 – 2014 (Web of Science)
Journal Ranking from JCR Q1 Q2 Q3 Q4
Number of Papers 9 0 1 1

International Journal Papers (11 SCI papers were published since 2009)

1.   Hui Wang*, Kam-Weng Tam, Wai-Wa Choi, Wen-Yao Zhuang*, Sut-Kam Ho, Wei Kang and Wen Wu, “Analysis of coupled cross-shaped resonator and its application to differential bandpass filters design,” IEEE Trans. Microw. Theory Tech. vol. 63, no. 1, January 2015.
JCR Journal Ranking: (30/247, Q1) in Engineering, Electrical & Electronic
2.
              
  Pedro Cheong, Ka-Fai Chang, Wai-Wa Choi, and Kam-Weng Tam “A highly integrated antenna-triplexer with simultaneous three-port isolations based on multi-mode excitation,” will appear in IEEE Trans. Antennas Propag. vol. 63, no. 1, 2015.
JCR Journal Ranking: (11/78, Q1) in Telecommunications
3.
              
  Wanchen Yang*, Kam-Weng Tam, Wai-Wa Choi, Wenquan Che and Hon-Tat Hui, “Novel polarization rotation technique based on an artificial magnetic conductor and its application in a low-profile circular polarization antenna,” IEEE Trans. Antennas Propag. vol. 62, no. 10, 2014. (Early Access in IEEExploer Digital Library)
JCR Journal Ranking: (11/78, Q1) in Telecommunications
4.
              
  Wanchen Yang*, Kam-Weng Tam, Wai-Wa Choi, Wenquan Che and Hon Tat Hui, “Novel polarization rotation reflective surface based on an artificial magnetic conductor and its application,” Electron. Lett. vol. 50, no. 21, pp. 1500 – 1502, October 2014.
JCR Journal Ranking: (141/247, Q3) in Engineering, Electrical & Electronic
5.
              
  Pedro Cheong, Ke Wu, Wai-Wa Choi and Kam-Weng Tam “Yagi-Uda antenna for multiband radar applications,” IEEE Antennas Wireless Propag. Lett., vol. 13, pp. 1065-1068, 2014.
JCR Journal Ranking: (15/78, Q1) in Telecommunications
6.
              
  Jin-Rong Mao*, Wai-Wa Choi, Kam-Weng Tam, Wenquan Che and Quan Xue, “Tunable bandpass filter design based on external quality factor tuning and multiple mode resonators for wideband applications,” IEEE Trans. Microw. Theory Tech., vol. 61, no. 7, pp. 2574 – 2584, July 2013.
JCR Journal Ranking: (30/247, Q1) in Engineering, Electrical & Electronic
7.
              
  Suyang Shi*, Wai-Wa Choi, Wenquan Che, Kam-Weng Tam, and Quan Xue, “Ultra-wideband differential bandpass filter with narrow notched band and improved common-mode suppression by DGS,” IEEE Microw. Wireless Comp. Letts., vol. 22, no. 4, pp. 185–187, April 2012.
JCR Journal Ranking: (52/247, Q1) in Engineering, Electrical & Electronic
8.
              
  Wai-Wa Choi, “Special section on recent progress in antennas and propagation conjunction with main topics of ISAP2010 Forward”, The IEICE Trans. of Communications, vol. E95-B no.1, January 2012.
JCR Journal Ranking: (227/247, Q4) in Engineering, Electrical & Electronic
9.
              
  Li Yang*, Pedro Cheong, Liang Han, Wai-Wa Choi, Kam-Weng Tam and Ke Wu “Miniaturized parallel coupled-line filter-antenna with spurious response suppression,” IEEE Antennas Wireless Propag. Lett., vol. 10, pp. 726 – 729, 2011.
JCR Journal Ranking: (15/78, Q1) in Telecommunications
10.
              
  Pedro Cheong, Ting-Shan Lv, Wai-Wa Choi and Kam-Weng Tam, “A compact microstrip square-loop dual-mode balun-bandpass filter with simultaneous spurious response suppression and differential performance improvement,” IEEE Microw. Wireless Compon. Lett. vol. 21, pp. 77 – 79, February, 2011.
JCR Journal Ranking: (52/247, Q1) in Engineering, Electrical & Electronic
11.
              
  Xiao-Hua Wang, Quan Xue and Wai-Wa Choi, “A novel ultra-wideband differential filter based on double-sided parallel-strip line,” IEEE Microw. Wireless Compon. Lett. vol. 20, pp. 471 – 473, August, 2010.
JCR Journal Ranking: (52/247, Q1) in Engineering, Electrical & Electronic
12.
              
  Wai-Wa Choi, Kam-Weng Tam and R. P. Martins, "Spurious suppressed microstrip bandpass filter with two transmission zeros,” Microwave and Optical Technology Lett., vol. 48, pp. 1979-1981, October 2006.
JCR Journal Ranking: (188 /247, Q4) in Engineering, Electrical & Electronic
13.
              
  Wai-Wa Choi, Kam-Weng Tam and R. P. Martins, "Design of microwave lumped and transversal bandpass filter with noise reduction,” Microwave and Optical Technology Lett., vol. 48, pp. 1161-1164, June 2006.
JCR Journal Ranking: (188 /247, Q4) in Engineering, Electrical & Electronic
Remarks    
*   PG students under my supervision

International Conference Papers (15 peer-reviewed papers were published since 2009)

1.   Ka-Heng Chan#, Chi-Seng Cheang# and Wai-Wa Choi, “ZigBee wireless sensor network for surface drainage monitoring and flood prediction,” will appear in Proc. The 19th International Symposium on Antennas and Propagation (ISAP2014), Kaohsiung, Taiwan, December 2 – 5, 2014.
2.   Wanchen Yang*, Wenquan Che, Wai-Wa Choi and Kam-Weng Tam, “A low-profile circularly polarized dipole antenna using a novel polarization rotation artificial magnetic conductor,” will appear in Proc. The 44th European Microwave Conference 2014 (EuMC2014), Fiera di Roma, Rome, Italy, October 2014.
1 of the Top 3 Conferences in Microwave Engineering
3.   Jin-Rong Mao*, Wenquan Che, Wai-Wa Choi, Kam-Weng Tam and Quan Xue, “Fully tunable filter design using tunable transformers and multiple mode resonators,” in IEEE MTT-S Int. Wireless Symp. Dig. (IWS2013), April 2013, pp. 1–3.
4.   Yuzhe Zhang#, Wai-Lon Chio#, Wen-Yao Zhuang*, Wai-Wa Choi and Kam-Weng Tam, “Size reduction of microstrip crossover using defected ground structure and its application in butler matrix,” in Proc. 2013 IEEE International Workshop on Electromagnetics (iWEM2013), 1 – 3 August, 2013, vol. 1, pp. 100 – 103, Hong Kong, China.
5.   Suyang Shi*, Wai-Wa Choi, Kam-Weng Tam, Wenquan Che, and Quan Xue, “Differential UWB power-distribution network with equal power ratio and out-of-phase single-ended outputs,” IEEE MTT-S Int. Microw. Symp. Dig., 2012, vol. 1.
1 of the Top 3 Conferences in Microwave Engineering
6.   Li Yang*, Wai-Wa Choi and Kam-Weng Tam, “Differential microstrip bandpass filter with dual-band responses using parallel-coupled line structure,” in Proc. 2012 Asia Pacific Microwave Conference (APMC 2012), vol. 1 pp. 28-30, Kaohsiung, Taiwan, December 4-7, 2012.
1 of the Top 3 Conferences in Microwave Engineering
7.   Wen-Yao Zhuang*, Pedro Cheong, Wai-Wa Choi and Kam-Weng Tam, “Novel filter-antenna using slot antenna and centrally loaded coupled line structure,” in Proc. The 16th Int. Symp. Antenna and Propagation (ISAP2011), 25 – 28 October 2011, Jeju, Korea.
8.   Chon Chio Leong*, Wai-Wa Choi and Kam-Weng Tam, “A tunable dual-band DGS stub tapped branch-line coupler,” in Proc. 2010 Asia-Pacific Microwave Conference (APMC2010), December 2010, pp. 1252-1255. Yokohama, Japan.
1 of the Top 3 Conferences in Microwave Engineering
9.   Li Yang*, Pedro Cheong, Wai-Wa Choi and Kam-Weng Tam, “A three-port integrated dual band filter-antenna module,” in Proc. The 15th Int. Symp. Antenna and Propagation (ISAP2010), November 2010, pp. 1029-1032, Macao SAR, China.
10.   Wen-Yao Zhuang*, Pedro Cheong, Wai-Wa Choi and Kam-Weng Tam, “An integrated open-loop resonator bandpass filter-slot antenna with stopband improvement,” in Proc. The 15th Int. Symp. Antenna and Propagation (ISAP2010), November 2010, pp. 1033-1036, Macao SAR, China.
11.   Bin-Kai Ou, Daniel Piscarreta, Pedro Cheong, Wai-Wa Choi and Kam-Weng Tam, “Open-loop stub-loaded dual-band resonator for solution sensing,” in Proc. The 15th Int. Symp. Antenna and Propagation (ISAP2010), November 2010, pp. 836-839, Macao SAR, China.
12.   Pedro Cheong, Sam-Ngai Lam#, Yao-Quan Qui#, Wai-Wa Choi and Kam-Weng Tam, “A tunable antenna-filter module for simultaneous UHF RFID-based power facility monitoring and partial discharge measurement,” in Proc. Int. Conf. Applications of Electromagnetism and Student Innovation Competition Awards, August. 2010, pp. 182-186, Taipei, Taiwan.
13.   K. K. Sun, Ting-Shan Lv, Kam-Weng Tam and Wai-Wa Choi, “A miniaturized dual-mode bandpass filter with spurious response suppression and its balun-bandpass extension,” in Proc. Cross Strait Tri-Regional Radio Science and Wireless Technology Conference (CSTRWC2009), August 2009, pp. 93. Tianjin, China.
14.   Chon Chio Leong*, Wai-Wa Choi and Kam-Weng Tam, “A tunable monopole antenna using double U-shaped defected ground structure with islands,” in Proc. The 14th Int. Symp. Antenna and Propagation (ISAP2009), Bangkok, Thailand, October 2009, pp. 783-786.
15.   Chon Chio Leong*, Wai-Wa Choi and Kam-Weng Tam, “Tunable bandstop element using double U-shaped defected ground structure with islands,” in Proc. Cross Strait Tri-Regional Radio Science and Wireless Technology Conference 2009 (CSTRWC 2009), Tianjin, China, 23 – 25 Aug. 2009.
16.   Wai-Wa Choi and Kam-Weng Tam, “A novel compact microstrip dual-band bandpass filter based on transversal filter structure and centrally loaded resonator with independent control of passbands,” in Proc. 2008 Asia-Pacific Microwave Conference (APMC2008), Hong Kong, China, December 2008, pp. 783-786.
17.   Wai-Wa Choi and Kam-Weng Tam, “A microstrip SIR dual-mode bandpass filter with simultaneous size reduction and spurious responses suppression,” in Proc. IEEE MTT-S International Microwave Workshop Series on Art of Miniaturizing RF and Microwave Passive Components, Chengdu, China. December 2008, pp. 116-119.
18.   K. M. Ho, H. K. Pang, Wai-Wa Choi and Kam-Weng Tam, “Design of compact microstrip resonator filter with projective DGS,” in Proc. Cross Strait Tri-Regional Radio Science and Wireless Technology Conference (CSTRWC2006), Macao, China, Aug. 2006, pp 120-122.
19.   Wai-Wa Choi, Kam-Weng Tam and R. P. Martins, “A compact microstrip transversal bandpass filter using grounded λ/4 resonator with capacitive stub,” in Proc. Microwave and Millimeter-wave Symposium of China, Shenzhen, China, Feb. 2006, pp. 582-585.
20.   Wai-Wa Choi, Kam-Weng Tam and R. P. Martins, “A novel microstrip transversal bandpass filter with simultaneous size reduction and spurious responses suppression,” in Proc. 2005 Asia-Pacific Microwave Conference (APMC2005), Suzhou, China, 4 – 7 Dec. 2005 pp. 508-511.
21.   Wai-Wa Choi, Kam-Weng Tam and R. P. Martins, “Improvement of gain compression in microwave lumped and transversal bandpass filters,” in IEEE MTT-S Int. Microwave Symp. Dig., Jun. 2005, Long Beach, USA, pp. 2171-2174.
22.   S. I. Hong, S. W. Fok, Wai-Wa Choi, Kam-Weng Tam and R. P. Martins, “A novel wiggly-line hairpin filter with 2nd spurious passband suppression,” in Proc. The 34th European Microwave Conference (EuMC2004), Amsterdam, Netherlands, Oct., 2004, pp. 1125-1128.
23.   Wai-Wa Choi, Kam-Weng Tam and R. P. Martins, “Microwave lumped and transversal bandpass filter using unequal source degeneration inductors for noise and selectivity improvement,” in Proc. Mediterranean Microwave Symposium(MMS2004), Marseille, France, Jun. 2004, Session 2B.
24.   K. M. Ho, H. K. Pang, Wai-Wa Choi and Kam-Weng Tam, “Novel T-DGS l/4 dual band impedance transformer,” in Proc. Mediterranean Microwave Symposium(MMS2004), Marseille, France, Jun. 2004, Session 3C.
25.   K. V. Chiang, Wai-Wa Choi and Kam-Weng Tam, “Source degeneration inductor based noise suppression scheme for microwave lumped and transversal bandpass filter,” in Proc. 2003 Asia-Pacific Microwave Conference(APMC2003), Seoul, Korea, Nov. 2003, pp.1961-1964.
26.   C. P. Chiang#, K. P. Lei#, Wai-Wa Choi, S. W. Ting, S. W. Fok4, S. I. Hong4 and Kam-Weng Tam, “Reliability analysis of a homodyne wireless LAN receiver subject to the impedance mismatch,” in Proc. International IEEE Conference on the Business of Electronic Product Reliability and Liability, Shenzhen, China, Jun. 2003, pp. 334-337.
27.   K. P. Lei#, C .P. Chiang#, Wai-Wa Choi and Kam-Weng Tam, "Novel coupled-line microstrip duplexer with high frequency isolation and 2nd spurious passband suppression," in Proc. 2002 Asia-Pacific Microwave Conference(APMC2002), Kyoto Japan, Nov. 2002, pp. 501-503.
28.   C. P. Chiang#, K. P. Lei#, Wai-Wa Choi and Kam-Weng Tam, “Mismatch effect on noise figure for WLAN receiver,” in Proc. The 45th Midwest Symposium on Circuits and System, Tulsa, Oklahoma, USA, 4-7 Aug. 2002, pp. 587-590.
29.   K. F. Chang, Kam-Weng Tam, Wai-Wa Choi and R. P. Martins, “Novel quasi-elliptic microstrip filter configuration using hexagonal open-loop resonators,” in Proc. 2002 IEEE International Symposium on Circuits and Systems, Phoenix, Arizona, USA, 26 – 29 May 2002, pp. 863-866.
30.   K. V. Chiang, Kam-Weng Tam, Wai-Wa Choi and R. P. Martins, “Noise performance of CMOS transversal bandpass filters,” in Proc. 2002 IEEE International Symposium on Circuits and Systems, Phoenix, Arizona, USA, 26 – 29 May 2002, pp. 871-874.
31.   S. W. Sin#, K. C. Lai#, K. V. Chiang, Wai-Wa Choi, Kam-Weng Tam and R. P. Martins, “An analytical linearization method for CMOS MMIC power amplifier using multiple gated transistors,” in Proc. The 4th International Conference on ASIC, Shanghai, China, 23 – 25 Oct. 2001, pp. 670-672.
32.   S. W. Sin#, K. C. Lai#, K. V. Chiang, Wai-Wa Choi Kam-Weng Tam and R. P. Martins, “A new IMD3 reduction approach based on composite effect of gm" and gds",” in Proc. IEEE CAS Workshop on Wireless Communications and Networking, 9 – 10 Aug. 2001, South Bend, Indiana, pp. 357-359.
33.   K. H. Chiang, K. V. Chiang, K. F. Lam, Wai-Wa Choi, Kam-Weng Tam and R. P. Martins, “Modular approach for high Q microwave CMOS active inductor design,” in Proc. The IEEE Int. Conf. on Electronics, Circuits and Systems (ICECS2000), 17 – 20 Dec 2000, Jounieh , Lebanon Dec. 2000, pp. 41-44.
34.   K. H. Chiang, K. V. Chiang, K. F. Lam, Wai-Wa Choi, Kam-Weng Tam and R. P. Martins, “Comparative study of microwave CMOS differential active inductor,” in Proc. The First Portugal-China Workshop on Solid-State Circuits, Shanghai, China, Oct. 2000, pp. 96-98.
35.   K. M. Lou, C. K. Ip, K. M. Ho, Wai-Wa Choi, Kam-Weng Tam and P. Vitor, “Vessel monitoring system using GPS/GSM/GIS for small city,” in Proc. The 6th Asia-Pacific Conference on Communications (APCC2000), Seoul, Korea, 30 Oct. – 2 Nov. 2000, pp. 470-474.
36.   Wai-Wa Choi, Kam-Weng Tam, P. Vitor and R. P. Martins, “Active feedback amplifier approach for microwave active filter,” in Proc. IEEE International Conference on Electronics, Circuits and System (ICECS1999), Pafos, Cyprus, 5 – 8 Sep. 1999, pp. 497-500.
37.   Wai-Wa Choi, Z. S. Guo “Compression scheme apply on internet facsimile gateway,” in Proc. of The 1998 International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC1998), Sokcho, Korea, Jul. 1998, vol. I, pp. 315 - 318.
Remarks    
*   PG students under my supervision
#   UG students under my supervision

Applied Research Achievements and Creative Works

List of Governmental Consultancy Projects

Reports, Summaries and Presentations to Government and Public

Invited Positions for Services on Informal Education

Organized Activities for Informal Education (Chair)


Service to the University and the Wider Community

University and Faculty/Unit Service

Management Positions

Committee Works

Student Affair Services

Seminars Organization

High School Outreach Actives Services

External Service

Services to Professional Societies

Services to Governmental Agencies

Editorial Works of Journal and Conferences

Judges and Panel

Conferences and Seminars Organization


Contact Details

Faculty of Science and Technology
University of Macau, E11
Avenida da Universidade, Taipa,
Macau, China

Room: E11-3036
Telephone: (853) 8822-8468
Fax: (853) 8822-2426
Email: welsyc