Antenna matching for bandwidth enhancement

Authors

  • Roman Kravchenko TDK-EPC, Austria
  • M. Stadler TDK-EPC, Austria
  • F. Rak TDK-EPC, Austria

DOI:

https://doi.org/10.1109/ICATT.2007.4425201

Keywords:

antennas, LTCC, broadband communication, matching

Abstract

A matching technique which simultaneously fulfills 2 tasks, matching and enhancement of the operation frequency band, is presented in this paper. As an example, matching for a 5-band mobile phone (GSM 850, GSM 900, GSM 1800, GSM 1900 and WCDMA 2100) has been examined. Two very simple inverted-L antennas with input impedances in range of 2 - j10 to 10 + j20 Ohms with two matching circuits are used to provide a 50 Ohm matching for all bands. LowBand: GSM 850 + GSM 900. HighBand: GSM 1800 + GSM 1900 + WCDMA 2100. The target for return loss was selected 3.5 VSWR. The rejection of LowBand at HighBand -and vice versa -is better than 25 dB, so no further diplexing would be needed in the front end. The size of one matching component is 1.6 times1.8 times 1.2 mm3. The overall antenna efficiency (at 50 Ohm terminal) is 52-60% min at LowBand and 65-70% at HighBand.

References

MATTHAEI, G.; YOUNG, L.; JONES, E.M.T. Microwave Filters, Impedance-Matching Networks, and Coupling Structures. Norwood, MA: Artech House, Inc., 1980.

ICATT 2007 cover

Published

2007-09-22

Issue

2007: ICATT’2007 - Proc. of VI Int. Conf. on Antenna Theory and Techniques

Section

Antennas for communications and broadcasting