A compact (33  ×  16  ×  1.6 mm3) and novel shaped hexa-band frequency-reconfigurable antenna with a very wide tuning band is proposed. The proposed antenna operates at two single band modes (i.e., 3.5 GHz and 4.8 GHz) and two dual band modes (i.e., 2.10 GHz, 4.15 GHz and 2.4 GHz, 5.2 GHz) depending upon the switching states. The lumped elements are used in the simulation environment to achieve tunable capacitance, which is responsible for frequency reconfigurability. The measured tuning capability of the fabricated antenna ranges from 2.1 to 5.2 GHz. The proposed antenna has a VSWR   1.3 for all the resonant bands. The radiation efficiency of the proposed structure ranges from 80.41% to 96% at the corresponding frequencies. The far field and the scattering parameters of the proposed antenna are analyzed using Computer Simulation Technology (CST) Microwave Studio 2014. The designed antenna, due to its compact and affordable geometry, can be easily integrated in the modern communication devices such as smart phones, laptops and other portable electronic devices. A prototype of the designed antenna is fabricated and measured using PIN diode switches to validate the simulation results. The proposed reconfigurable antenna demonstrates a reasonable agreement between the measured and simulated results.

Design and analysis of a hexa-band frequency reconfigurable antenna for wireless communication

A novel dual branch multiband compact slotted antenna for digital broadcasting, wireless and sub 6 GHz 5G is presented. Antenna achieves multiband characteristics at (750–790 MHz) Digital broadcasting, (1.41–1.45 GHz) wireless medical telemetry, (2.10–2.14 GHz) Universal Mobile Telecommunication Service (UMTS), (3.44–3.51 GHz) WiMAX/sub 6 GHz 5G, (3.80–3.87 GHz) Sub 6 GHz 5G, (5.17–5.20 GHz) wireless local area network (WLAN) and (5.97–6.38 GHz) fixed satellite communication by introducing slots in the form of inverted U and E shape having varied branch lengths and full ground plane. The antenna has an overall size of 30 × 30 × 1.6 mm3. The proposed antenna achieves compact operation along with an omnidirectional radiation pattern having gain and efficiency in the range over 1.1 dBi and 78% for the proposed frequency bands. The antenna is fabricated after optimizing the geometrical dimensions where measured results match well with simulated ones.

Multiband inverted E and U shaped compact antenna for Digital broadcasting, wireless, and sub 6 GHz 5G applications

A novel miniaturized multiband reconfigurable fractal slot antenna for switchable GPS/GNSS/Bluetooth/WiMax/X-band is reported. By utilizing a Koch fractal in the radiating part miniaturization of about 78.8% and 86% are achieved in volume and active patch area respectively. Multiband operations at 1.47–1.65 GHz (BW = 11.5%) GPS, 2.2–2.43 GHz (BW = 9.9%) Bluetooth, 3.4–3.89 GHz (BW = 13.4%) middle WiMAX, 5.61–5.84 GHz (BW = 4%) upper WiMAX and 9.8–10.73 GHz (BW = 9.05%) X-band, are achieved by slotted ground approach in conjunction with Complementary Split Ring Resonator (CSRR). Frequency reconfiguration characteristics in the antenna is accomplished by placing a PIN diode in the ground plane; thus making the antenna to exhibit switchable radiations at 1.91–2.34 GHz (BW = 20.73%) Bluetooth, 3.72–3.89 GHz (BW = 4.46%) middle WiMAX, 4.92–5.33 GHz (BW = 8.0%) upper WiMAX and 10.16–10.70 GHz (BW = 5.1%) X-band, under “ON” condition. During “OFF” condition, antenna exhibits switchable performances at 1.59–1.84 GHz (BW = 14.57%) GPS/GNSS, 3.77–4.12 GHz (BW = 8.87%) middle WiMAX, 5.1–5.35 GHz (BW = 4.78%) upper WiMAX and 10.27–10.62 GHz (BW = 3.35%) X-band. The antenna has a compact area of 35 × 30 mm2, and exhibits acceptable gain, stable radiation patterns and good impedance matching at the targeted frequencies.

A miniaturized multiband reconfigurable fractal slot antenna for GPS/GNSS/Bluetooth/WiMAX/X-band applications

This paper presents a hexa-band frequency reconfigurable planar antenna, printed on a 1.6 mm thicker FR 4 substrate and backed by a truncated ground plane. The given antenna operates in four different frequency modes, depending on the state of the two lumped element switches. The proposed antenna works at six frequencies, 2.10, 2.40, 3.35, 3.50, 5.28, and 5.97 GHz. These frequency bands are dedicated to useful wireless applications, including 3G Advanced (2.10 GHz), Wireless Fidelity (Wi-Fi) (2.40 GHz), WiMAX (3.35 GHz), WiMAX (3.5 GHz), WLAN (5.28 GHz) and fixed-satellite and mobile satellite services (5.97 GHz). Satisfactory gain of 1.96, 2.20, 2.671, 2.81, 3.80, and 3.88 dBi, efficiency of 92.5, 94.5, 94.56, 95.0, 93.8, and 97.0% and bandwidth of 332, 485, 1020, 1080, 512, and 465 MHz has been obtained at 2.10, 2.40, 3.35, 3.50, 5.28, and 5.97 GHz, respectively. The modeling and simulations are conducted in CST MWS (2014). The simulated reflection coefficient and radiation pattern are validated in antenna measurement facility. In addition, the specific absorption rate of the antenna on a flat section of human body is also studied. The antenna is compact, low profile, and vastly suitable for multi-band wireless devices.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1759078718000776

A multi-band switchable antenna for Wi-Fi, 3G Advanced, WiMAX, and WLAN wireless applications

A novel miniaturized slotted multiband antenna is presented in this article. The antenna consists of a kite-shaped slot in the radiating patch to obtain miniaturization, C- and G-shaped slots in the ground plane to incorporate multiband operation and a microstrip feedline to obtain an impedance matching. The aforementioned miniaturization method results in about 50% reduction in active patch area and about 36% reduction in volume of the proposed design, as compared to the conventional antenna. G-shaped slot is used to obtain operations at 3.6 and 5.8 GHz, while C-Shaped slot is used to obtain operations at 6.9 and 9.5 GHz. The antenna has an active patch area of only 384 
 $$\hbox {mm}^{2} (24\times 16\,\hbox {mm}^{2})$$
 , and the entire performance analysis of the antenna are carried out using HFSS v.13.0 simulation software. The proposed design operates at about 3.58 (WiMAX), 5.9 (WLAN), 6.72 (Satellite TV), 8.51 and 9.76 GHz (X-band) with $${S}_{11}<-\,10\,\hbox {dB}$$
 bandwidth of about 1.95% (3.54–3.61 GHz), 3.5% (5.88–6.09 GHz), 1.7% (6.68–6.80 GHz), 4.4% (8.36–8.74 GHz) and 3.96% (9.4–9.78 GHz), respectively. The proposed structure is compact in size, simple in construction, low profile, easy to fabricate, exhibits good impedance matching, moderate gain and stable radiation characteristics across the operational bandwidths.

A miniaturized slotted multiband antenna for wireless applications

This research presents a novel four band frequency reconfigurable antenna for 1.6 (Global Navigation Satellite system (GNSS)), 2.5 (Lower Worldwide Interoperability for Microwave Access (WiMAX)), 5.8 (Wireless local area network (WLAN)) and 9.8 GHz (X-band) frequency bands. The antenna has a compact size of 0 . 18 λ 0 × 0.18 λ 0 × 0.0096 λ 0 at lower resonance of 1.8 GHz and is printed on FR4 material with height (h) = 1.6 mm, dielectric constant ( ( e r ) = 4.4 and loss tangent ( δ ) = 0.02. Multiband phenomenon in the antenna is achieved by etching trapezoidal slot in the radiating monopole and rectangular slots in the ground plane. Frequency reconfiguration in the proposed structure is achieved by placing PIN diode switch between rectangular slot placed in the ground plane. During OFF state, the antenna exhibit quad band with S11

A multiband reconfigurable slot antenna for wireless applications

A novel method of miniaturizing an antenna using concentric slots is discussed in this research. Initially, a circular Ultrawideband (UWB) antenna is designed with −10dB impedance bandwidth of 115%. This antenna is miniaturized by using concentric ring like slots in the radiating patch to a dimension of 0.32λo × 0.32λo × 0.014λo (at lower resonant band of 2.84 GHz) with −10dB impedance bandwidth of about 125%. These concentric slots increases the inductance and line capacitance of circular patch thereby maintaining the UWB characteristics even though the conventional antenna is miniaturized. The proposed design has a good impedance matching, radiation pattern at the entire UWB operation. The proposed design is intended for the use of various wireless application such as WLAN, WiMAX, WiFi etc.

A miniaturized truncated ground plane concentric ring shaped UWB antenna for wireless applications

A truncated radiating patch circularly polarized antenna for Indian Regional Navigation Satellite System (IRNSS) application is discussed. Circular polarization in the proposed design is achieved through corner truncation of the radiating patch and the use of coaxial feed mechanism. The proposed design has a dimension of 0.31 λ 0 × 0.31 λ 0 × 0.009 λ 0 at a frequency of 1.176 GHz. The antenna resonates at a frequency of 1.176 GHz with a simulation S 11 r ) = 6.15, loss tangent (δ) = 0.0019 and height (h) = 2.54 mm. The proposed design achieves a gain of 0.68 dB, good impedance matching and stable radiation.

A Corner truncated circularly polarized antenna for IRNSS application

A compact planar slotted multiband antenna for WLAN and WiMAX applications is presented in this research. The antenna consists of a trapezoidal shaped slot as the radiating patch, and rectangular and U-shaped slots as the ground plane. These slots changes the surface current distributions of the antenna, resulting in the increase in current path length, thereby making the antenna operate at multiband. The antenna has an electrical dimension of 0.21 λ 0 × 0.23 λ 0 ×0.01λ 0 at a lower frequency of 2.4 GHz, and is analyzed on FR4 substrate using HFSS v.13.0 simulator. The antenna has a wide-bandwidth operation at the lower resonance with S11 11 <−10 dB bandwidth of about 3.3% (5.8–6 GHz). Good impedance matching and stable radiation characteristics are observed across the operational bandwidth of the proposed antenna configuration.

Mohammed Muzammil Khaleeq

Papers

A multiband reconfigurable slot antenna for wireless applications

A miniaturized truncated ground plane concentric ring shaped UWB antenna for wireless applications

A Corner truncated circularly polarized antenna for IRNSS application

A slotted multiband antenna with wide-bandwidth operation at lower band for WLAN/WiMAX applications