# Dual-Band UWB Monopole Antenna for IoT Applications +
###### Abstract  
A dual-band UWB coplanar waveguide monopole antenna is presented in this paper. The antenna proposed in this paper consists of an FR4 substrate, two ground planes, and a rectangular patch. The size of the antenna proposed is 24 \(\times\) 25 \(\times\) 1 mm\({}^{3}\) with a slit of length and width of 5.7 and 0.5 mm, respectively. We received two operating bands, a C- and Ku-band, with both Bi and Omni-directional radiation patterns. The bandwidth values of the first (3.65-7.49) GHz and second (11.5-13.4) GHz band of the proposed antenna are 3.9 GHz and 1.7 GHz, respectively. The proposed antenna operating at a frequency 5.8 GHz has a maximum bandwidth of 4.5 GHz and minimum bandwidth of 1.6 GHz. The characteristics of this antenna show that the antenna proposed in this paper is suitable for dual-band and UWB communication systems. We achieved a wide bandwidth by improving the ground plane.  
monopole antenna; dual-band UWB +
Footnote †: Corresponding: 2023 by the authors.  
technology has many applications, including medical imaging, military communications, and radar [5].  
UWB with band rejection capabilities has been developed to reduce interference in wireless applications. To achieve these band rejection capabilities, several slits can be made in feed, ground, or patch [6]. Using a slot to boost bandwidth, a reduced antenna size was proposed in [7]. New antenna designs are being proposed to meet the stringent requirements of smart devices and make them compatible with previous wireless communication systems [8; 9]. Dual-band antennas provide a reliable and robust wireless connection in often difficult-to-reach situations; these are also considered energy-harvesting antennas. In dual-band antennas, 2.4 GHz and 3.6 GHz are the two most used frequencies. The 3.6 GHz option has a higher frequency and, as a result, a narrower range. Due to its higher frequency, more information can be handled simultaneously in a 3.6 GHz antenna. On the other hand, the frequency of 2.4 GHz is relatively low. Due to this, it can cover greater distances and penetrate more. Depending on the area, we can switch between these two frequencies or use both. The monopole antenna fed by a coplanar waveguide (CPW) has gained so much attention because of its unique features, such as a larger impedance bandwidth, a more straightforward structure, less conductor loss, and improved radiation efficiency.  
Compact wideband or multi-band antennas for handheld communication devices are challenging to design because they must meet general bandwidth requirements; offer consistent gain and symmetric radiation patterns; and be compact in size, easy to fabricate, and lightweight. Because of the diverse operating requirements of communication devices, there has been an increase in interest in finding antennas that cover multiple frequency bands, such as S-band (2-4 GHz), WiMAX (3.3-3.8 GHz), 5G mid bands (3.3-3.8 GHz, 4.4-4.9 GHz), C-band (4-8 GHz), WLAN (5.15-5.825 GHz), UWB (3.1-10.6 GHz), and X-band (8-12 GHz). By inserting slits or slots into the patch/ground plane at appropriate locations, a narrow band microstrip patch antenna can be converted into a multi-band antenna. Many band-notched UWB antennas have been reported in recent studies; for example, an arc-slot in the patch was reported in [10], and a slot with an embedded tuning stud was reported in [11; 12]. Cutting a \(\pi\)-slot [13], inserting a slit [14], and placing parasitic elements near feed have also been mentioned in the literature [15; 16]. The resonances and stopband are influenced by the placement of the slit, as well as its shape and size. Assume the slit length on the patch/ground plane is a quarter or half wavelength. In that case, it can excite the higher modes around the fundamental method, allowing various operating bands to be achieved. The antenna proposed in this paper operates in C-band and Ku-band. The function of any slot antenna depends on the substrate's material, feed type, antenna geometry, and slot position.