Reduction In Return Loss Research Articles

An Ultra-Thin Multi-Band Logo Antenna for Internet of Vehicles Applications

In this paper, an ultra-thin logo antenna (LGA) operating in multiple frequency bands for Internet of Vehicles (IoVs) applications was proposed. The designed antenna can cover five frequency bands, 0.86–1.01 GHz (16.0%) for LoRa communication, 1.3–1.36 GHz (4.6%) for GPS, 2.32–2.71 GHz (16.3%) for Bluetooth communication, 3.63–3.89 GHz (6.9%) for 5G communication, and 5.27–5.66 GHz (7.1%) for WLAN, as the simulation indicated. The initial antenna started with a modified coplanar waveguide (CPW)-fed circular disk monopole radiator. To create extra current paths and further excite other modes, the disk was hollowed out into the shape of the car logo of the Chinese smart EV brand XPENG composing four rhombic parasitic patches. Next, four triangular parasitic patches were inserted to improve the impedance matching of the band at 5.6 GHz. Finally, four metallic vias were loaded for adjusting resonant points and the return loss reduction. Designed on a flexible substrate, the antenna can easily bend to a certain degree in complex vehicular communication for IoV. The measured results under horizontal and vertical bending showed the LGA can operate in a bending state while maintaining good performance. The proposed LGA addresses the issue of applying one single multi-band antenna to allow vehicles to communicate over several channels, which relieves the need for a sophisticated antenna network.

THE EFFECT OF DIFFERENT DIELECTRIC MATERIALS ON RADIATION FEATURES OF SLOTTED PATCH ANTENNAS FOR 6G COMMUNICATION SYSTEMS

In this study, patch antenna structures with rhombic shaped slots have been investigated for 6G communication systems. Four different dielectric materials, such as arlon, polyamide, polyimide, and silicon, have been selected for antennas with the same design procedure. In this way, the effects of slots on frequency responses for different dielectric substrates have been searched. The slots are parametrically analyzed in terms of edge size and location, and the designs are completed for values with the lowest return loss levels. The amount of return loss reduction in slotted antennas is 38% and 42% for arlon and polyamide, respectively, while the reduction is 28% and 8% for polyimide and silicon, respectively. In addition, bandwidth increases in slotted antennas vary according to the dielectric substrate material. The bandwidth increases have been 0.05 GHz, 0.426 GHz, 0.839 GHz, and 0.475 GHz for arlon, polyamide, polyimide, and silicon substrates, respectively. With these results, the study will give an insight to the researchers who will design antennas in 6G bands in terms of the effects of materials on antenna characteristics and will give inspiration for new designs.

Reduction in Return Loss of a Novel Reconfigurable Antenna at 3.4 GHz by FR4 Substrate Using Double PIN Diodes

Aim: The main objective of the project is to reduce the return loss of a reconfigurable antenna at 3.4 GHz by using FR4 substrate with Double PIN diodes. Materials and Methods: Two diode configurations of single PIN diode and Four diodes configuration of double PIN diodes are used with a sample size of 6. Results: From HFSS simulation software Return Loss(-30.2dB) and VSWR (1.10) of Reconfigurable Monopole antenna is improved by FR4 substrate using Double PIN diodes. Attained significance ratio(P=0.05) in statistical analysis. Conclusion: Double PIN diode of a reconfigurable Monopole antenna performs well (Return Loss is reduced by -7dB) when compared with a single PIN diode of a reconfigurable Monopole antenna.

Low-power ultra-wideband LNA employing CS–CD current-reuse and gain-controller resistor technique in 0.180-μm CMOS technology

In this paper, a low-power ultra-wideband low noise amplifier (LNA) is presented. The combination of dual resonance network and current-bleeding technique offers high and flat voltage gain and low noise figure (NF), and also, the gain-controller resistor technique causes better control of voltage gain to achieve flatter gain. Furthermore, the CS–CD (Common-Source Common-Drain) current-reuse technique provides output return loss reduction and eliminates buffer stage in LNA design. It has been shown that using this scheme, noticeable improvement has been obtained in the frequency range of 2–11 GHz. This improvement consists of minimum noise figure value as 2.5 dB, the maximum value of 4.2 dB and average noise figure lower than 3 dB in a wide frequency range, from 4 to 10 GHz. The proposed LNA achieves the average voltage gain of 12.35 dB with a variation of 0.85 dB in the frequency range of 2–11 GHz. Input and output return losses are below − 10 dB and IIP3 of the proposed structure is − 3 dBm. The proposed LNA consumes 9.52 mW in 1-V supply voltage. Moreover, the size of the structure is 0.54 mm2 in TSMC 180-nm technology.

A Novel Microstrip-to-Microstrip Vertical Via Transition in X-Band Multilayer Packages

This paper investigates a novel X-band microstrip-to-microstrip vertical via transition with matching pads loaded signal via. This design has been proposed for a multilayer substrate package. The matching pads, which are located in the center of the signal via on each ground layer, are adopted to further improve the impedance matching level and thus attain better signal transition performance. A physics-based equivalent circuit modeling approach has been employed for this research. The right angle MS-to-MS via transition was also designed using this technique. The simulatedS-parameters indicate that the match-pad design made a breakthrough in achieving an approximate −15 dB wide-band return loss reduction. The measuredS-parameter of MS-to-MS transition showed that return loss with the matching pads is better than that without the matching pads.

A new design and analysis of a hexagonal PBG microstrip antenna

ABSTRACTThis work aims to analyze the factors that influence the radiation properties of dualband microstrip antenna using periodic structures based on Photonic Band Gap with hexagonal symmetry. An increase in bandwidth and a reduction of return loss for the second operating band of the antenna were observed. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2147–2151, 2015

English

An Antenna is one of the essential parts for microwave communication. Since it help both transmitting and receiving the information. An antenna is a device that is made to efficiently radiate and receive the radiated electromagnetic waves. The microstrip antennas have attractive features such as low profile, small size and weight, low cost, printed directly on circuit board and easy to analysis and fabricate. For reduction of return loss, stacked patch and Double U- slot on patch of microstrip antenna concept is used. A rectangular microstrip patch antenna has been investigated and its performance has been analyzed with the aid of Ansoft HFSS version 13.microstrip patch antenna, stacked patch microstrip antenna and double U- slot stacked patch microstrip antenna have been designed for S- band to reduce return loss of antenna.

Return Loss Reduction of Molded Bonding Wires by Comb Capacitors

The objective of this paper is to demonstrate reduction of return loss of bonding wires using comb capacitors attached to bonding pads. The measured results show the magnitude of return loss of molded bonding wires was improved by 17.7 dB at 900 MHz and by 8.63 dB at 2.4 GHz with reference bonding pads, respectively. With attachment of comb capacitors, the return loss at the other end of the bonding wires (i.e., leads) was also reduced by 8.6 dB at 900 MHz and by 2.4 dB at 2.4 GHz.

Return loss reduction of integrated grating-assisted optical add/drop multiplexer by control of the reflective spectrum

Return loss, a key characteristic of the optical add/drop multiplexer (OADM), has become an urgent and challenging problem in the development of the integrated grating-assisted OADM. In this paper, a novel design approach to achieve low-return-loss integrated grating-assisted OADMs is proposed. The reflective spectrum is properly controlled to ensure the backreflection peaks can fall outside the wavelength channel, so that the return loss can be kept low. Meanwhile, it can also be found that the tolerance in fabrication process is enlarged. Simulation on the null-coupler OADM shows that, by employing the proposed method, the return loss at both input- and add-port can drop to lower than -53 dB from -38 and 0 dB, respectively, and be kept below -53 dB even with a tilt angle ranging from 3.2/spl deg/ to 3.5/spl deg/. The application of this method on the design of the symmetric-coupler OADM is also presented.