Design of ultra-compact ISM band implantable patch antenna for bio-medical applications

In this paper, an ultra-compact implantable antenna for biomedical applications is proposed. The proposed implanted meandered compact patch antenna is implanted inside the body at a depth of 2 mm. The proposed antenna was designed with Roger RO3003 (ɛr = 3) as substrate with an overall size of dimensions 5 × 5 × 0.26 mm3. The radiating element is a square patch antenna with different size rectangular slots and coaxial feeding. The proposed implantable antenna resonates at 2.45 GHz (from 2.26 to 2.72 GHz) frequency with a bandwidth of 460 MHz and a gain of −22.6 dB. The specific absorption rate has been considered for health care considerations, and the result is within the limits of the federal communication commission. The measured and simulated scattering parameters are compared, and good agreements are achieved. The proposed antenna is simulated and investigated for biomedical applications suitability.

A Wider Impedance Bandwidth Dual Filter Symmetrical MIMO Antenna for High-Speed Wideband Wireless Applications

This research article reports a compact fractal 4 × 4 UWB extended bandwidth MIMO antenna with physical dimensions of 44 × 44 mm2 for high-speed wireless applications. The reported antenna comprises four fractal radiating elements that are symmetrical and placed orthogonal to each other with a respective rectangular ground printed on the opposite plane. A higher isolation is achieved between the radiating elements by the placement of a fractal patch orthogonally and no separate decoupling structure is required. The antenna offers a −10 dB transmission capacity of 2.84–15.88 GHz. The fractal radiating element, which is embedded by an inverted T-type stub placed within a rectangular slot and an etched rotated C-type slot, provides band-stop filters for WiMAX (Worldwide inter-operability for Microwave Access) and WLAN (wireless local area network)-interfering bands. The key parameters of diversity performance are compared by simulation and measurement (fabricated prototype) of ECC (envelope correlation coefficient), DG (directive gain), TARC (total active reflection coefficient) and CCL (channel capacity loss). The antenna offers an omnidirectional radiation pattern with an average gain of 3.52 dBi.

Metasurface Superstrate Beam Steering Antenna with AMC for 5G/WiMAX/WLAN Applications

A beam-steering antenna based on non-uniform metasurface superstrate and AMC, operating at 3.5 GHz, is presented. The antenna can steer the beam along θ = -18° and 18° with the superstrate and along θ = 0° in the absence of the superstrate with almost zero scan loss. Antenna structure consists of a top layer of non-uniform metasurface superstrate made of a 20 × 20 grid of electrically-small square-shaped metallic pixels while the bottom part consists of AMC with a grid of 5 × 5 pixels. The radiating element, CPW-fed monopole antenna, is placed between AMC and superstrate. The fabricated prototype shows desired beam steering in directions of θ = -18°, 0°, and 18° while maintaining uniform realized gain of 5.5 dB and matches well with simulations.

Quadruple Band-Notched Compact Monopole UWB Antenna for Wireless Applications

A printed quadruple band-notched ultra-wideband (UWB) antenna characteristic is presented. The designed UWB antenna has a size of 32 mm × 30 mm × 1.6 mm and covers an impedance bandwidth off 2.9–14.5 GHz for the entire frequency band. The entire frequency band maintains voltage standing wave ratio (VSWR) <2, except at WiMAX (3.1–3.6 GHz), WLAN (4.92–6.12 GHz), downlink of X-band for satellite communication systems (7.5–8.4 GHz), and X-band (10.2–11 GHz). By inserting a pair of L-shaped slots into the radiating element, a H-shaped resonator and rectangular split-ring resonators are closely arranged to the microstrip feed-line, alongside the measured impedance bandwidth of 129%. The fabricated antenna radiation pattern and return loss is presented.

Metamaterial inspired multi-split square shaped printed antenna for WLAN applications

This paper describes the design of a compact dual band microstrip antenna based on metamaterial inspired split ring radiating element and a complementary spilt ring resonator (CSRR). The antenna has a very compact dimension of 20×20×0.8 mm3. It covers the 2.5/5.2/5.8 GHz frequencies, pertaining to IEEE 802.11 b/g/a standards suitable for WLAN applications with a -10dB impedance bandwidth of 250 MHz and 860 MHz. The CSRR creates a negative permittivity region, thus providing miniaturization of the antenna and the introduction of additional split gaps in the radiating element creates a positive permeability within the desirable frequency range, yielding better impedance matching. The negative properties of those structures are verified using S-parameter retrieval method. A prototype of the proposed antenna is fabricated and the measured results are fairly in good agreement with the simulation results. Dipole like radiation patterns are observed at both the operating frequencies. The measured peak gains are 0.58 dBi, 1.27 dBi and 2.10 dBi at 2.5, 5.2 and 5.8 GHz respectively.

A Circularly Polarized, Flexible and Compact Quad-Band Wearable Antenna for Off-Body Communication Applications

A compact wearable textile antenna with multiband and circular polarization characteristics is proposed in this work for Wireless Body Area Networks (WBAN). An asymmetrically connected vertical stub as a radiator with the partial ground for quad-band (3.03–3.76[Formula: see text]GHz, 5.48–6.24[Formula: see text]GHz, 7.10–7.40[Formula: see text]GHz, 7.93–8.22[Formula: see text]GHz) operation and horizontal stubs on the radiator with L-slots in the ground is proposed for the triple band (3.16–3.22[Formula: see text]GHz, 7.25–7.36[Formula: see text]GHz and 7.93–8.08[Formula: see text]GHz) circularly polarized radiation. Jeans fabric is used as substrate with dielectric constant [Formula: see text] and loss tangent ([Formula: see text]). The dimensions of the proposed antenna are [Formula: see text][Formula: see text]mm3. Various conductive fabrics are investigated and analyzed as a radiating element. The proposed jeans antenna provides the gain ([Formula: see text] dB) and radiation efficiency ([Formula: see text]%) for all operating bands. The impact of the human body right arm loading on the antenna has been presented in terms of the reflection coefficient ([Formula: see text]) and gain using the CST Microwave studio simulation environment. The proposed antenna provides stable performance under bending conditions and the SAR values that are under acceptable limits ([Formula: see text][Formula: see text]W/kg for 10[Formula: see text]g of tissue). The flexibility, compactness and radiation properties make it suitable as a wearable textile antenna for off-body communication applications.

The Design of a Wideband Antenna with Notching Characteristics for Small Devices Using a Genetic Algorithm

This paper presents the design and realization of a compact printed ultra-wideband (UWB) antenna with notching characteristics for compact devices using a genetic algorithm. The antenna is capable of mitigating an adjacent sub-band ranging from 3.75 to 4.875 GHz, mainly used by many applications and standards such as WiMAX, WLAN and sub-6-GHz. The notch band functionality is achieved by etching out two symmetrical slots from the pentagonal radiating element. The simulation and measured results demonstrate that the proposed antenna overperformed compared with state-of-the-art antennas in terms of compactness with an overall size of 20 mm×15 mm×0.508 mm. Moreover, the proposed design shows a large bandwidth in the UWB region with a fractional bandwidth of 180% with respect to the center frequency of 5.25 GHz. The antenna also presents omnidirectional radiations all over the operation band and a good return loss performance.

Design and Implementation of Super Wide Band Triple Band-Notched MIMO Antennas

In this article, a triple band-notched super-wideband (SWB) monopole antenna is designed and manufactured. The measured working frequency band (out of the filters working band) ranges from 2.5 to 20 GHz. A single radiating element is utilized to analyze and implement various MIMO antennas, with isolation between the antenna ports higher than 15 dB. Two parallel-fed elements SWB MIMO antenna and four parallel-fed elements SWB MIMO antennas are presented. Metallic barriers with different shapes are used to improve the isolation among ports from a low unacceptable value of 12 dB to a value higher than 20 dB within most of the working frequency band. S-parameters of the presented SWB MIMO antennas experimentally shows that antennas perform well up to 20 GHz, which is the highest frequency supported by the available Vector Network Analyzer used in the S parameters measurements. Satisfactory performance is observed up to 50 GHz by computer simulations using the CST software.

Wide Scanning Angle Millimetre Wave 1 × 4 Planar Antenna Array on InP at 300 GHz

The design of a uniformly spaced 1 × 4 linear antenna array using epitaxial layers of benzocyclobutene over an InP substrate is demonstrated. The array elements are conjugately matched with a uni-travelling carrier photodiode at the input. The phased array is optimised to counteract mutual coupling effects by introducing metal strips with isolated ground planes for each radiating element. The proposed antenna array can provide a gain of 10 dBi with a gain variation of ±3 dB. The array operates over a bandwidth of 10 GHz (295–305 GHz) with a wide scanning angle of 100° in the broadside.