Broadband Cross-shaped Microstrip-fed Slot Antenna

In general, conventional bow‐tie slot antennas have broadband characteris. Microstrip‐fed bow‐tie‐shaped meander slot antenna with compact and broadband characteristics - Wi - 2005 - Microwave and Optical Technology Letters - Wiley Online Library. Considerable approaches with novel F shaped slot antenna and a planar antenna that is printed on a substrate with two rectangular corners cut off have been proposed in,. In 11 with meandering split-ring slot, the proposed antenna consists of a modified rectangular slot, a pair of symmetrical inverted-L strips.

A numerical simulation and an experimental implementation of T-shaped microstrip-fed printed slot array antenna are presented in this paper. The proposed antenna with relative permittivity 4.3 and thickness 1.0mm is analyzed by the finite-difference time-d

tation of T-shaped microstrip-fed printed slot array an-tenna are presented in this paper. The proposed antenna

with relative permittivity 4.3 and thickness 1.0mm is ana-lyzed by the finite-difference time-domain (FDTD) method. The dependence of design parameters on the bandwidth characteristics is investigated. The measured bandwidth of twin-slot array antenna is from 1.37 GHz to 2.388 GHz, which is approximately 53.9 % for return loss less than or equal to -10 dB. The bandwidth of twin-slot is about 1.06 % larger than that of single-slot antenna. The meas-ured results are in good agreement with the FDTD results.

As microwave equipments require low profile and light-weight to assure reliability, an antenna with these characteris-tics is essentially required and a microstrip antenna satisfies such requirement. Microstrip antennas have conformal struc-ture, low cost, and ease of integration with solid-state devices as well as low profile and lightweight. But the microstrip an-tennas have a narrow bandwidth which is about 10-20 %. In the last decade, many researchers have studied the bandwidth widening technique of microstrip antennas [1]-[3]. A popular method is the use of parasitic patches, either in another layer (stacked geometry) [4] or in the same layer (coplanar geome-try). However, the stacked geometry has the disadvantage of increasing the thickness of the antenna, and the coplanar ge-ometry has the disadvantage of increasing the lateral size of the antenna [5]. Most microstrip-fed structures of the printed slot antenna have been used by making the microstrip-fed struc-tures [5] across the center of slot [7], [8]. The conventional cen-ter-fed transverse slot antennas have a large value of radiation impedance, so that it is very difficult to match in practice. To solve these problems, short-tuning and open-tuning stubs which offset from the center of a slot to the end were proposed [9]. Narrow slot width is good for impedance matching [10] but with wide slot width, a special matching circuit at the feed-ing port is needed for good impedance matching.

Broadband Cross-shaped Microstrip-fed Slot Antenna Tuner

This paper presents the characteristics of single-slot and twin-slot antennas with T-shaped feed line. A T-shaped micro-strip feed line is proposed to match the input impedance for narrow as well as wide slot antennas. When the T-shaped feed line is used, we can extend the bandwidth in proportion to the slot width. In this case, the proposed antenna leads to the im-

Manuscript received August 18, 2000; revised February 16, 2001.

Yong-Woong Jang is with the Department of Electronic Communication Engineering, Keukdong College, Chungcheongbuk-Do, Korea. (phone:+82 43 881 3317, e-mail: ywchang@telecom.kdc.ac.kr)

Broadband Cross-shaped Microstrip-fed Slot Antenna Booster

ETRI Journal, Volume 23, Number 1, March 2001 Yong-Woong Jang 33