# A Low-Cost CPW-Fed Multiband Frequency Reconfigurable Antenna for Wireless Applications
## 1 Introduction
The antenna performed in a continuously switching frequency range from 1.17 to 1.58 GHz by loading the varactor between the patch and the ring. Reconfiguration using RF-MEMS gave lower loss and increased Q factor compared to PIN diodes and varactors [13]. Amongst these switching techniques, PIN (Positive-Intrinsic-Negative) diodes are considered to be low cost with sound isolation, easy fabrication, and low insertion loss for optimal performance. They are very consistent and compact as they tend to increase switching speeds and decrease resistive capacitance in both states, i.e., ON and OFF. CPW feed slot and folded slot antennas have been reconfigured to alter the resonant frequency by switching the slot length [14]. Previous reported works have utilized bias lines or vias for activation of PIN diodes, which make the circuit complicated and degrade the performance of the overall antenna system. Therefore, in this work, the biasing circuit is integrated into the same antenna to make it simple, and no vias are used. The effective length of the antenna is controlled by PIN diodes. [PERSON] et al. [15] reported L-shaped and U-shaped slots using three pin diodes for long term evolution (LTE) and WLAN applications, whereas its substrate has an antenna element on both sides. A pattern and frequency reconfigurable microstrip-based antenna is presented that has three operational states using five pin diodes; unidirectional at 5.4 GHz, omnidirectional at 2.4 GHz, and both unidirectional and omnidirectional functionalities operate simultaneously [16]. Similarly, three pin diodes are implanted on the ground plane of a frequency reconfigurable antenna to control switching states [17]. Its radiating patch is designed as a square for WLAN, WiMAX, and Bluetooth applications. The FR4-based frequency reconfigurable antenna presented by [PERSON] et al. [18] resonates between different modes, i.e., narrow band, ultra-wideband, and dual-band. The ground is slotted with four pin diodes that result in switching. Five PIN diodes are embedded in the microstrip frequency reconfigurable antenna, with six states switchable between 2.2 GHz to 4.75 GHz [19]. However, there are three drawbacks in the design; complexity due to the large number of switches; large size; and low impedance bandwidth. It must be noted that the concept of achieving wideband performance from the tapered structure is based on [20; 21], where the authors utilized a printed tapered monopole antenna (PTMA) and investigated the ultra-wideband (UWB) behavior. They showed their step by step approach to bandwidth dispensation from corresponding rectangular to tapered and then from circular/cylindrical to tapered structures. They also compare the bandwidth performance in each case. Therefore, in this paper, a CPW-fed, compact, cedar-shaped, multiband frequency reconfigurable antenna is proposed. The main advantage of this antenna is its ability to tune to different resonant frequencies. The length of the radiating patch is changed by the lumped elements, mainly PIN diodes in this design, to achieve different resonant frequencies ranging from 2 GHz to 10 GHz. The paper is arranged in the following manner. Section 2 gives step by step guidelines and the approach used in designing the proposed antenna. Section 3 investigates and provides the refined antenna's simulated vs. measured results in different scenarios. Section 4 compares the proposed work with the recently published state of the art designs in the literature, which is followed by a conclusion section.