46 research outputs found
A Simply Accessed Approach of 2D Shaping Liquid Metal in Microwave Device Applications
No full textIn this letter, a simply accessed approach of 2D shaping liquid metal (LM) is presented. This approach allows a microwave device to take advantage of LM in both stretchability and removability. This approach is achieved based on the Young-Laplace theory of liquid surface tension, as well as the surface oxidization that LM possess. An application example of this approach is demonstrated by a functional changeable microwave device. The proposed device operates in antenna mode when LM is not incorporated. Then, it can change to resonator mode after filling 2D shaped LM into fluidic channels. To our knowledge, it is the first device that is capable of changing its function using LM. The measured gain of the proposed microwave device is 7.1 dBi at 2.68 GHz when it operates in antenna mode. The measured insertion loss of the proposed microwave is 1.8 dB at 2.62 GHz when it operates in resonator mode
Circuits and Antennas Incorporating Gallium-Based Liquid Metal
No full textThis article reviews the application and technology advancement of gallium (Ga)-based liquid metal (LM) in high-frequency circuits and antennas. It discusses the material properties of common LMs, the fluidic channels used to contain LM and their manufacturing techniques, and the actuation techniques, which are all critical for the design and implementation of LM-based devices. LM’s fluidic and pliable nature, together with its excellent electrical, thermal, and rheological (i.e., fluid flow) properties, provides some unique and innovative solutions to flexible/wearable electronics, reconfigurable circuits, and antennas. This article provides a comprehensive review of a wide range of LM-enabled high-frequency circuits and antennas, including interconnects and transitions, reconfigurable passive circuits (such as resonators, filters, and couplers), switches, phase shifters, reconfigurable antennas, flexible and wearable antennas, and metamaterials (i.e., periodic materials with properties not found in nature). This article presents various design concepts and implementation techniques, highlights key capabilities, and discusses the challenges and opportunities with the use of Ga-based LM materials
X-Band Reconfigurable Phase Shifters Based on SIW and Liquid Metal Technologies
No full textThis paper presents three reconfigurable phase shifters operate at X-band and designed utilizing liquid metal (LM). The phase shifters operate at 10 GHz and they have very low insertion loss performance and able to handle high levels of radio frequency (RF) power. Besides, the proposed phase shifters able to achieve a total of 360° phase shift and they are compact in size as they are designed using substrate integrated waveguides (SIW). This enable the proposed phase shifters to be integrated within SIW based feeding structures to realize complete phased array antenna systems. The phase shift is realized by inserting a series of liquid metal vias in the SIW. When a single or multiple via connection is needed, the via hole is filled with liquid metal and conversely, the liquid metal is withdrawn from the via when the connection is no longer required.</p
10 GHz Low Loss Liquid Metal SIW Phase Shifter for Phased Array Antennas
No full textThis article presents a proof of concept demonstrator for a pair of novel phase shifters based on substrate integrated waveguide (SIW) technology. Gallium-based liquid metal (LM) is used to reconfigure each phase shifter. This article presents LM phase shifters that, for the first time, have a phase shifting range of 360°. The phase shifters have a small electrical size, and they are intended for use within phased array antenna applications. This article also presents a design procedure for the phase shifters. The procedure has been used to design two phase shifters operating at 10 GHz. The design process can be readily scaled for operation at other frequencies. The proposed phase shifters are reciprocal and bidirectional, and they have very low insertion loss (IL). A series of reconfigurable LM vias are used to achieve the phase shift. Each of LM via is activated once a drill hole is filled with LM and it is deactivated once LM is removed. Using this method, it is possible to achieve a phase shift step ranging from 1° to 100° using a single LM via. Moreover, the overall phase shift can be extended to 360° by employing several LM vias in series inside the SIW. The proposed phase shifters have an IL lower than 3 dB and provide a total phase shifting range of approximately 360° in eight steps of approximately 45° each. This enables the proposed two phase shifters to have an extraordinary figure of merit (FoM) of 131.3°/dB and 122.4°/dB
mm-Wave Low-Cost 3D Printed MIMO Antennas With Beam Switching Capabilities for 5G Communication Systems
No full textThis paper presents designs and prototypes of low cost multiple input multiple output (MIMO) antennas for 5G and millimetre-wave (mm-wave) applications. The proposed MIMOs are fabricated using 3D printing and are able deliver beams in multiple directions that provide continuous and real time coverage in the elevation of up to {\mp }30^{\circ } without using phase shifters. This equips the proposed MIMO with a superior advantage of being an attractive low cost technology for 5G and mm-wave applications. The proposed MIMO antennas operate at the 28 GHz 5G band, with wide bandwidth performance exceeds 4 GHz and with beam switching ability of up to {\mp }30^{\circ } in the elevation plane. The direction of the main beam of the single element antenna in the MIMO is steered over the entire bandwidth through introducing 3D printed walls with different heights on the side of the 3D printed radiating antenna. Unlike all other available beam steering techniques; the proposed wall is not only able to change the direction of the beam of the antenna, but also it is able to increase the overall directivity and gain of the proposed antenna and MIMO at the same time over the entire bandwidth
High aperture efficient slot antenna surrounded by the cavity and narrow corrugations at Ka‐band and Ku‐band
No full textA design criterion for a small, compact, high-aperture-efficient antenna is proposed in this study. The proposed criterion is validated experimentally through fabricating and testing two prototypes for Ku-band and Ka-band applications. The proposed antenna design consists of a resonance slot perforated in an aluminium plate and surrounded by a cavity and two corrugations. The proposed Ku-band antenna has an aperture efficiency of 74.3% and a measured gain of 12.2 dBi at 13 GHz, while the Ka-band antenna resonates at 28.5 GHz with a peak aperture efficiency of 78% and a gain of 12.9 dBi. The gain of both antennas is dramatically boosted by the radiation from the cavity and corrugations, resulting in a significant enhancement in the aperture efficiency
Dual-Layer Corrugated Plate Antenna
No full textThis letter presents a subwavelength slot-fed high-gain dual-layer corrugated plate antenna for X-band applications. The antenna is realized by placing a second corrugated layer that has three radiating slots on top of the traditional corrugated plate antenna. The addition of the second layer improves the gain and bandwidth of the proposed antenna. Compared to a traditional single-layer corrugated plate antenna, the proposed dual-layer antenna has higher gain, lower sidelobe level, narrower half-power beamwidth, and better impedance bandwidth. A prototype of the proposed antenna is built and tested, and the measured results show that the antenna has a peak gain of 16.3 dBi at 11.3 GHz. The gain of the proposed antenna has been improved by more than 4 dBi due to coupling more energy to the second layer's three slots. Finally, the operating principles of the proposed antenna are also discussed and analyzed thoroughly
