Wideband CPW-Fed Spiral-Shaped Slot Antenna
for Wireless Applications
and Wen-Cheng Lai
Lunghwa University of Science and Technology, Taoyuan City, Taiwan
Ming Chi University of Technology, New Taipei, Taiwan
Received in final form January 12, 2018
Abstract—A new compact design of CPW-fed wideband (WB) spiral-shaped slot antenna is proposed.
The proposed antenna has a compact size with overall dimensions 37´33 mm and is fabricated on FR4
substrate with dielectric constant e
= 4.4 and thickness h = 1.6 mm. With the different length of the
spiral-shaped slots, simulated and experimental results of the antenna are suitable for WB operations. The
–10 dB bandwidth of the WB antenna from measurement is approximately 115.2% (2.36–8.53 GHz). The
proposed antenna provides nearly omni-directional radiation characteristics. The new antenna
configuration operates in several different bands: 2.4, 3.5, 5.2, 5.5, and 5.8 GHz covering 2.4/5.2/5.8 GHz
WLAN bands and 2.5/3.5/5.5 GHz WiMAX bands. The results for S
, far-field H- and E-plane radiation
patterns and gain of the proposed antennas are presented and discussed. The agreement between
measured results and full-wave simulation validates the feasible configuration of the proposed antennas.
The rapid developments in the wireless communications industry demand novel multiband antennas
design. To meet this demand, multiband antennas have been introduced to support various applications as it
can maintain reasonable gain and suitable radiation patterns (RP). Recent research on multiband antennas is
very active because of the continuous demands of high performance circuits from modern communications
and electronic systems.
In recent years, several printed coplanar waveguide (CPW)-fed monopole antennas and planar
geometries such as square, triangular, and circular have been reported, providing wide impedance
In , a new broadband CPW-fed circularly-polarized slot antenna with an open slot is studied and the
broadband circular polarization can be achieved. A new compact dual wideband CPW-fed inverse
triangular-shape antenna is proposed. The antenna performance is enhanced with a dual-band uni-planar
EBG reflector . In , a compact CPW-fed multiband circular slot antenna design loaded with arc-shaped
metallic strips is presented and shown that the arc-shaped metallic strips yield the multiple resonant modes
for multiband operation. Two miniaturized designs of CPW-fed slot antennas are investigated and the slot
radiators are shortened by employing meandered thin strips or interdigitated capacitors (IDC) as the reactive
We study a compact CPW-fed wideband (WB) antenna that the design consists of two spiral-shaped
slots. The antenna is currently under consideration for use in the multiband system which has the advantages
of low profile, lightweight, ease of fabrication. Some of the antennas have been proposed before [5–9].
In this paper, the spiral-shaped slots of the WB antenna have been presented and fabricated. By varying
the length of the spiral-shaped slots, the geometrical configuration of the antenna can obtain a good
impedance matching. In addition, the proposed antenna operates at specified frequencies and can be
ISSN 0735-2727, Radioelectronics and Communications Systems, 2018, Vol. 61, No. 4, pp. 180–183. © Allerton Press, Inc., 2018.
Original Russian Text © L.-C. Tsai, W.-C. Lai, 2018, published in Izvestiya Vysshikh Uchebnykh Zavedenii, Radioelektronika, 2018, Vol. 61, No. 4, pp. 239–244.
This work was supported by Lunghwa University of Science and Technology under Grant R1301050001.