Design of a Novel Split-Bowtie Slotted Multi- Resonant Antenna Osama W. Ata and Mutaz I. Jawadeh Electrical Engineering Dept., Faculty of Engineering, Palestine Polytechnic University, Hebron, Palestine Email: oata@ppu.edu, oata@fulbrightmail.org Abstract—This article demonstrates a novel design of a split- bowtie slotted multi-resonant antenna. The design process was inspired from previous research of integrating a slot of a similar profile to the outer boundary of a rectangular patch antenna. The followed approach presents steps of proposed antenna evolution, which starts with a bowtie- shape slotted antenna and a coaxial feed to a final design with a split-bowtie-shaped slot, and a double transmission line feed. Polar dimensions of the outer boundary (radii and angle) and slot profiles together with the dimensions of the feed, whether coaxial or transmission line, were considered as parameters for optimization. Four antennas were accordingly studied, which led to the final split-bowtie- shaped antenna IV. These designs were performed utilizing a special simulation package called “CST Microwave Suite” that included the optimizer “Genetic Algorithm”. The final design offers 4 simultaneous bands from a single split- bowtie-shaped slot; a big advantage of unnecessary integration of a set of complicated slots on front and ground planes. Further, the antenna finds applications in mobile GSM and LTE bands 900/1800 MHz and 2.1 GHz, together with the satellite communications band 1.25 GHz. It is therefore simple, non-reconfigurable, easy to fabricate, designed on a single copper layer, with a low cost FR4 substrate and a plane copper ground. Index Terms—Split-bowtie-shaped slot, multi-resonant, double-slotted, GSM 900/1800, LTE 2.1, GPS 1.25 I. INTRODUCTION Multi resonant antennas have received much interest from researchers and users of various wireless applications with benefits of size compactness and reduced cost. While microstrip antennas can be etched in different shapes and sizes, bowtie antennas can be designed to serve narrow and ultra-band frequency ranges. Bowtie antennas have been extensively applied in radar [1]–[3] and mobile base-stations [4]. Some researchers [5] studied its robust characteristics over the frequency range (3 GHz to 11 GHz). Others [6] studied the effect of changing the angle on the return loss and the radiation patterns. They concluded that “doubling the angle to 80 had no effect on return loss but on a narrower half power beam-width (HPBW) in the radiation pattern.” Rounding [7] the side edges of the bowtie antenna, on the other hand, “improved the return loss, the input impedance and the stability of radiation patterns.” Manuscript received November 12, 2021; revised December 17, 2021; accepted January 18, 2022. Corresponding author: Osama W. Ata (email: oata@ppu.edu). On a different front, “changing the position of certain slit configurations on various parts of the antenna arms” was studied [8] and was found to “produce resonances at around 3 GHz, 5 GHz and 7 GHz frequencies.” Inserting “circular and polygon shaped slots on the bowtie arms” were introduced [9] in a new antenna with “multi- resonant bands” that could be utilized for many wireless applications. By “etching slots of different lengths in a bowtie patch,” the authors in [10] were able to introduce “bent monopoles that produced various operating frequencies.” As the lengths of the introduced multiple bent monopoles met the quarter wavelength resonance condition, they successfully produced a slotted bowtie antenna with three bands; “300 MHz within the 2GHz to 3 GHz range, 300 MHz within the 3 GHz to 4 GHz range, and 600 MHz within the 5 GHz to 6 GHz range.” More recently, the authors in [11] proposed a novel triple-band dipole antenna, where slots were etched on the bowtie patch. Accordingly, “three bent dipoles with different lengths that corresponded to different operating frequencies were formed.” The proposed antenna produced three bandwidths; “270 MHz in the 2.3 GHz to 2.7 GHz range, 910 MHz in the 3.1GHz to 4.1 GHz range and 1.25 GHz in the 4.5 GHz to 6.00 GHz range, with a satisfactory reflection coefficient of less than -10 dB.” The authors in [12] presented a multiband reconfigurable bowtie slot antenna using switchable pairs of slots. The proposed approach is based on “the integration of two pairs of slots on the two sides of the antenna to create new bands.” The properties of the bowtie antenna have been used to design a “reconfigurable frequency antenna with a high realized gain, operating in the WiFi, WiMAX, and WLAN with four operating modes, one in single band, two in dual band and one in triple band.” Kavith [13] investigated the design and performance of “Sierpinski Fractal Bowtie antenna to obtain multiband behavior.” The evaluation of “Sierpinski fractal antenna was made up to two iterations.” The overall dimension of Sierpinski fractal antenna was 110x70 mm 2 .The final design was able to operate at frequencies “1.4 GHz, 3.5 GHz, 4.6 GHz and 7.4 GHz with gains of 6.4 dB, 9.2 dB, 6.7 dB and 9.1 dB respectively.” Kumar et al. [14] investigated a “bowtie antenna on FR4 substrate (40 mm  58 mm  1.5 mm) with a modified symmetric split ring resonator (SRR) that was implemented beneath the substrate, as meta-material loading, which consisted of two circles and three circles.” Each circle was broken into four quarter circles by four rods. The effect of “the modified symmetric SRR locations and consequent geometry” was analyzed. In both configurations, 4 bands International Journal of Electrical and Electronic Engineering & Telecommunications Vol. 11, No. 4, July 2022 ©2022 Int. J. Elec. & Elecn. Eng. & Telcomm. 317 doi: 10.18178/ijeetc.11.4.317-324