A compact and miniaturized implantable antenna for ISM band in wireless cardiac pacemaker system

A tiny and compact implantable antenna for wireless cardiac pacemaker systems is designed. The antenna works in the Industrial Scientific Medical (ISM) frequency band (2.4–2.48 GHz). The size of the antenna is greatly reduced with the adoption of a high dielectric constant medium and a folded meander structure. The volume of the antenna is 4.5 mm3, and the size is only 3 mm × 3 mm × 0.5 mm. Based on the literature research, it was found that the design was the smallest among the same type of implanted antenna. The antenna is optimized and loaded with a defective slotted structure, which improves the efficiency of the overall performance of the antenna and thus the gain thereof. The antenna maintains good impedance matching in the ISM frequency band, covering the entire ISM frequency band. The actual bandwidth of the antenna is 22%, with the peak gain of − 24.9 dBi. The antenna is processed and manufactured in such a manner that the simulation keeps consistent with the actual measurement. In addition, the specific absorption rate of the antenna is also evaluated and analyzed. The result shows that this kind of antenna is the best choice to realize the wireless biological telemetry communication in the extremely compact space of the wireless cardiac pacemaker system.

Conformal Quad-Port UWB MIMO Antenna for Body-Worn Applications

A conformal four-port multiple-input-multiple-output (MIMO) antenna operating at 2.4 GHz and ultrawideband (UWB) is presented for wearable applications. The unit element of the MIMO antenna is a simple rectangular monopole with an impedance bandwidth of 8.9 GHz (3.1–12 GHz). In the monopole radiator, stubs are introduced to achieve 2.4 GHz resonance. Also, a defect is introduced in the ground plane to reduce backside radiation. The efficiency of the proposed antenna is greater than 95%, and its peak gain is 3.1 dBi. The MIMO antenna has an isolation of >20 dB, and the estimated specific absorption rate (SAR) values for 1 gm of tissue are below 1.6 W/Kg. The size of the four-port MIMO antenna is 1.38λ0 × 0.08λ0 × 0.014λ0.

Gain and Bandwidth Enhanced Optimized Notch Loaded Microstrip Antenna for 5G Applications

In this paper, a rectangular patch antenna is presented loaded with T-shaped notch as well as having truncated corner for the enhancement of gain and bandwidth which is bring into play for mid band of 5G applications. With design frequency of 3 GHz, this prototyped design antenna having 50 Ω microstrip line feed for impedance matching and simulation has been performed using IE3D Mentor Graphics simulation software. Fractional impedance 51.3% has been observed from 2.39 to 4.04 GHz. An enhanced peak gain of 5.05 dBi and maximum directivity of 6.214 dBi has been observed at 4.22 GHz and 4.34 GHz respectively.

An Eight Element Dual Band Antenna for Future 5G Smartphones

The demand of 5G in modern communication era due to its high data rate, reliable connectivity and low latency is enormous. This paper presents a novel dual band antenna resonating at two distinct bands allotted for 5G services. The proposed antenna is composed of inverted L shape probes comprising a rectangular defected ground structure. The propose antenna covers 3.4–3.6 GHz and 5.4–5.6 GHz spectrum. In propose MIMO system, the efficiency ranges from 52 to 69% with peak gain of 3.1 dBi. The proposed antenna system is sufficiently isolated with minimum value of 13 dB and ECC less than 0.05 among any two radiating elements. Similarly, the channel capacity is found to be 38 and 39.5 at both resonating bands at 20 dB SNR and diversity and mean effective gains lies in acceptable range. The radiation characteristics of the proposed design shows that the proposed antenna is providing good diversity characteristics and SAR values have demonstrated to be safe for user vicinity. The proposed dual band antenna prototype is developed tested. With the measured results obtained, the MIMO system proposed can be seen as vital candidate for 5G LTE band 42 and 46 services.

A Hybrid Antenna with Equal Beamwidth in Two Frequency Bands for Radar Applications

This paper presents a novel hybrid antenna with equal beamwidth in two frequency bands for short-range radar applications. The proposed design consists of a 2 × 2 patch array and a SIW-fed dielectric rod antenna. The two kinds of radiators are responsible for the 5.8 GHz and 24 GHz ISM bands, respectively. Pencil beams are obtained in both lower and upper bands. The beamwidth generated by the dielectric rod can be flexibly tuned to coincide with that of the patch array. Magneto-electric (ME) dipole, composed of a slot and two parasitic monopoles, is constructed to replace the conventional 3-D waveguide feeder, which can excite the dielectric rod effectively. The complementary structure is helpful to obtain a pencil beam. The 2 × 2 patch array has the size of 70 × 70 mm2 and is fed by a four-way power divider. Due to no overlapping radiating aperture, the two radiators can work independently with high port isolation. The measured peak gain in the two bands is 12.5 dBi and 12.7 dBi. The measured 3-dB beamwidth at 5.8 GHz and 24 GHz is 42° and 39° in x-z plane, and 43° and 42° in the y-z plane. The proposed antenna features a small beamwidth difference in two frequency bands, thus being attractive for dual-band radar systems.

Dual-Band Millimeter Wave Microstrip Patch Antenna with StubResonators for 28/38 GHz Applications

A dual band monopole antenna with triangle stubs operated at 28/38 GHz applications is introduced. The introduced dual band antenna is used for next 5G applications. The introduced antenna is designed on a Rogers RT 4003 with height h = 0.203 mm, dielectric constant ɛr = 3.55 and over dimensions of 12×12×0.237 mm3. The simulated results show that the presented design has two bands, the first one is from 25.9 to 30.4 GHz and the second is from 36.4 to 40.2 GHz with peak gain of 4.54 dB, 4.21 dB in the first and second frequencies respectively. The simulated radiation efficiency for the first and second frequencies is 94% and 96.6%, respectively. There are some small discrepancies between simulated and measured findings due to the fabrication and measurement equipment.

4 × 4 MIMO Antenna System for Smart Eyewear in Wi-Fi 5G and Wi-Fi 6e Wireless Communication Applications

This paper proposes a small-slot antenna system (50 mm × 9 mm × 2.7 mm) for 4 × 4 multiple-input multiple-output (MIMO) on smart glasses devices. The antenna is set on the plastic temple, and the inverted F antenna radiates through the slot in the ground plane of the sputtered copper layer outside the temple. Two symmetrical antennas and slots on the same temple and series capacitive elements enhance the isolation between the two antenna ports. When both temples are equipped with the proposed antennas, 4 × 4 MIMO transmission can be achieved. The antenna substrate is made of polycarbonate (PC), and its thickness is 2.7 mm εr=2.85, tanδ=0.0092. According to the actual measurement results, this antenna has two working frequency bands when the reflection coefficient is lower than −10dB, its working frequency bandwidth at 4.58–5.72 GHz and 6.38–7.0 GHz. The proposed antenna has a peak gain of 4.3 dBi and antenna efficiency of 85.69% at 5.14 GHz. In addition, it also can obtain a peak gain of 3.3 dBi and antenna efficiency of 82.78% at 6.8 GHz. The measurement results show that this antenna has good performance, allowing future smart eyewear devices to be applied to Wi-Fi 5G (5.18–5.85 GHz) and Wi-Fi 6e (5.925–7.125 GHz).

A Wideband Reflector-Backed Antenna for Applications in GPR

A resistively loaded wideband slotted patch antenna with optimized performance on lower frequencies is proposed for ground-penetrating radar (GPR) applications. The proposed design is backed by an optimized reflector composed of a periodic array of square loop elements, which enhances the antenna’s gain and directivity. The antenna shows good radiation characteristics and ease of integration with the GPR systems. The proposed structure features a compact size and wide bandwidth covering from 0.6 to 4.6 GHz. The peak gain of 7 dBi is achieved. The fabricated prototype of the antenna along with an integrated optimized reflective surface has overall dimensions of 18 × 22 × 5 cm3. The measured results validate the antenna’s performance in both free space and sandy medium, which enlighten its use for GPR applications.

FULLY TRANSPARENT METAMATERIAL AMC BACKED CPW FED MONOPOLE ANTENNA FOR IOT APPLICATIONS

In this paper, a fully transparent antenna comprising of an Artificial Magnetic Conductor (AMC) backed Co-planar Waveguide (CPW) fed dual-ring monopole is presented. The monopole antenna and AMC structure achieve transparency due to the use of AgHT-8 conductive oxide and Plexiglas substrate. Measured antenna performance shows an impedance bandwidth of 5.3 – 6 GHz (12.4%) in the U-NII-1 to U-NII-4 frequency band with a peak gain of 5.7 dBi which is approximately an increase of 4.5% and 3.9 dBi, respectively, as compared to the standalone antenna. The simulation and the measurement results agree well with each other which proves the validity of the proposed design. To the best of our knowledge, the proposed antenna is the first fully transparent antenna design combining a transparent radiator and a transparent AMC structure.

A Novel Shape Compact Antenna for Ultrawideband Applications

Nowadays, more attention has been given into ultrawideband by dint of its extraordinary features over narrowband communication systems. This study presents a novel compact with tilted square frames shape antenna with partial ground plane. The proposed antenna is printed on commercially available Fr4 substrate with relative thickness of 1.6 mm. The antenna has compact dimensions of 14 × 18 mm2 with bandwidth ranging from 3.3 to 11.5 GHz. The peak gain obtained is 1.4 dBi with omnidirectional radiation characteristics throughout the entire bandwidth. The proposed antenna is fabricated, and the developed prototype measured results, which well agree with simulated results. With the performance parameters obtained and the well agreed measured results, the proposed antenna is well suitable for Wi-Fi, ISM, and UWB applications.