Multibeam Array Antenna with Compact Size Butler Matrix for Millimeter-Wave Application

New radio wave technologies of millimeter-wave (mmWave), compact cell size, and multi beam base station are introduced with the recent development of the 5G mobile system. The Butler Matrix (BM) feed circuit is the most preferable candidate for the 5G mobile system since it can achieve multi beam radiation patterns at the array antenna, provide structural compactness and produce good multi beams. The BM circuit is typically built on a single dielectric substrate. However, in this single-substrate structure, the micro strip line connecting several circuit elements in the BM spans over a large area, resulting in significant feeding loss in the millimeter frequency band. In this study, a compact size circuit configuration of BM is proposed, where the original single-substrate structure is modified into a two-substrate stacking structure. The via-hole is designed to connect the two substrates with minimal path loss. The BM is built for the 28 GHz band with four inputs and four outputs. The phase delay is optimized using via-hole to produce the phase difference of ±45º and ±135º. The coupling for the hybrid is -3 dB, while the transmission coefficient of -6 ± 3 is achieved from the BM structure and, the return loss (Sii) for both input and output ports are less than -10 dB. The two-substrate BM is combined with the rectangular patch antenna and the via-hole patch antenna in a planar configuration of 0.5 λ0 spacing to obtain the radiation patterns. When the Port 1 through Port 4 of the BM are fed, four beams are created, with peak gains of 11.2 dBi, 9.87 dBi, 10.2 dBi, and 11.7 dBi, respectively, towards +16°, -35°, +39°, and -12°. The analysis includes the radiation performance from the ideal value and from the BM input. Three-dimensional representations of good multibeam radiation patterns are obtained after each input signal of the BM is fed

Multibeam Array Antenna with Compact Size Butler Matrix for Millimeter-Wave Application

New radio wave technologies of millimeter-wave (mmWave), compact cell size, and multi beam base station are introduced with the recent development of the 5G mobile system. The Butler Matrix (BM) feed circuit is the most preferable candidate for the 5G mobile system since it can achieve multi beam radiation patterns at the array antenna, provide structural compactness and produce good multi beams. The BM circuit is typically built on a single dielectric substrate. However, in this single-substrate structure, the micro strip line connecting several circuit elements in the BM spans over a large area, resulting in significant feeding loss in the millimeter frequency band. In this study, a compact size circuit configuration of BM is proposed, where the original single-substrate structure is modified into a two-substrate stacking structure. The via-hole is designed to connect the two substrates with minimal path loss. The BM is built for the 28 GHz band with four inputs and four outputs. The phase delay is optimized using via-hole to produce the phase difference of ±45º and ±135º. The coupling for the hybrid is -3 dB, while the transmission coefficient of -6 ± 3 is achieved from the BM structure and, the return loss (Sii) for both input and output ports are less than -10 dB. The two-substrate BM is combined with the rectangular patch antenna and the via-hole patch antenna in a planar configuration of 0.5 λ0 spacing to obtain the radiation patterns. When the Port 1 through Port 4 of the BM are fed, four beams are created, with peak gains of 11.2 dBi, 9.87 dBi, 10.2 dBi, and 11.7 dBi, respectively, towards +16°, -35°, +39°, and -12°. The analysis includes the radiation performance from the ideal value and from the BM input. Three-dimensional representations of good multibeam radiation patterns are obtained after each input signal of the BM is fed

5G beam-steering 2×2 butler matrix with slotted waveguide antenna array

In this research paper, substrate integrated waveguide (SIW) was proposed as a technique by realizing bilateral edge walls to produce a compact 5G beam-steering antenna at 24 GHz. The beam forming network is produced using SIW directional coupler perform as 2×2 Butler Matrix (BM) fed with SIW slotted waveguide antenna array. The output signal is steered from -29 degrees and +29 degrees when the signal is fed to the respective input ports. If one of the input ports is fed, the signal is evenly distributed between the adjacent output ports with 90 degree constant phase shift. The compact size of directional coupler was designed by longitude slots on the surface of SIW substrate with bandwith of 16.85% at the operating frequency. The proposed antenna produce gain of 6.34 dB at operating frequency and the promising outcome of the beam steering make proposed design suitable for 5G communications especially with tracking capabilities

Wireless Power Transmission

Wireless Power Transmission is a process to supply power through an air gap without using any wires or physical link. This transmission is based on the Inductive coupling technique. In converting the electricity to an electromagnetic field, two coils are used as transmitter coil and receiver coil. The transmitter coil is powered by alternating current and creates a magnetic field, which is further converted into a usable voltage across the receiver coil

Flexible stepped impedance resonance antenna for early breast cancer detection

Breast cancer is affecting almost 17 million people worldwide by 2020. In order to detect cancerous tumours, earlier stage diagnosis is identified to be the effective ways to alleviate the cancer risk. Practically, x-rays mammography, diagnostic ultrasound and tomography are among the common technology used in tumour detection. However, limitation arises where some breast cancer is not detected due to poor malignant/benign cancer tissue contrast. As an alternative, microwave radiation techniques are introduced due to inexpensive, accurate 3D imaging data, and comfortable to the patient. Based on these advantages, in this proposed research paper, microwave radiation antenna techniques are proposed. Antenna radiating patch is designed from coplanar waveguide with stepped impedance resonance (SIR) on flexible substrate, polydimethylsiloxane (PDMS). The antenna design is placed to be in contact with breast skin to enhance the detection sensitivity. The proposed antenna covers the front section of the breast for different tumour cases locations, which detect the parameter changes respectively. Comparison between normal tissue and tumour tissue performance in terms of magnetic field distribution, electric field, current density and directivity performance has been analysed using Computer Simulation Technology software (CST™). The research proposed a coplanar waveguide (CPW) fed slot antenna that able to detect cancerous tissue modelled by a phantom breast. Results of simulations indicate good signs of developing the design into a real microwave imaging system in a short time coming

Wearable Textile Antenna Using Thermal-Print of Clothes Iron for the Indoor Wireless Remote Monitoring

Wearable technology has grown tremendously throughout the time and is well known in transmitting or receiving the data for the remote monitoring in the telehealth applications. However, the existing wearable technology including the textile-antennas have limitation due to the high cost material, challenging fabrication, metal fatigue, porous and produce high loss. To address this issue, in this research, a low cost method using thermal-print of clothes iron is proposed. A low cost material of conductive carbon is used where no sintering or fabrication process is needed while provide the affordable fabrication cost. The textile antenna had return loss, S11 of −31.6 dB, the gain of 4.1 dB, the bandwidth of 6.9%, while the directivity was 3.812 dB at 5.8 GHz. The antenna prototype provides a convenient and unobtrusive communication subject to flexing and bending. In the prototype module testing, the transceiver antenna can transmit and receive the signal effectively up till 3 m’ coverage. Moreover, after repeated flexing, the surface and RF performance of the textile antenna did not degrade, so it can be a suitable device in the future generations, especially in indoor wireless remote monitoring

Self-powered Solar Patch Antenna at 5.8 GHz for Wireless Surveillance Monitoring

A microstrip patch antennas (MPA) with self-powered ability have shown great interest especially in providing low-cost, green electricity and reliable continuous signal, for wireless surveillance monitoring systems. Although MPA has a low profile, lightweight, and inexpensive, the conventional MPA has limitations in terms of bandwidth and gain, where these two components are im portant towards the antenna’s performance. A battery-powered device tends to drain quickly over time and is bulky to transport. In this paper, a new design of a self-powered MPA that integrates a defective ground structure (DGS) and short- ing pin techniques are introduced. The MPA results show a return loss of less than −10 dB, directivity of 7.2 dB, a bandwidth improvement of 57.81%, and a gain of 6.36 dB. The proposed MPA is then connected to a solar cell circuit design for a self-powered system. In the system configuration, the XL4015 DC/DC buck converter’s input is directly connected to the 20-W solar panel, the output to a TS5828 5.8 GHz transmitter, and the First-person view (FPV) camera to power up the MPA. The system can operate up to 16.5 m away from the receiver and 15.5 m away from the transmitter, enable the proposed system to serve as a self-powered wireless surveillance monitoring system at 5.8 GHz