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Advanced Microstrip Antennas for Vehicular Communication
Published in Praveen Kumar Malik, Planar Antennas, 2021
A frequency bandwidth reconfigurable ultrathin antenna examined in this section is made of parasitic circular components and an open-ended circular ring. The bandwidth reconfigurability is attained by controlling the biasing conditions of the incorporated PIN diode. This reconfigurable bandwidth can help a vehicular band communication system to cover the necessary bandwidth through switching. The proposed antenna is appropriate for the LTE (1.9–2.025 GHz), GSM-1900 (1850–1990 MHz), UMTS (1920–2170 MHz), V2I IEEE 802.11p (5.850–5.925 GHz), V2V, Mobile Satellite Service (forward link: 1980–2010 MHz, reverse link: 1980–2010 MHz), DSRC, and WLAN 802.11a/n (5.710–5.835 GHz). The proposed layout is experimentally validated with a shark-fin radome enclosure and a large ground plane. The examination is also conducted on dielectric permittivity effects of the radome on antenna performance yields suggests the radome with relative permittivity 2–2.1 for modern practical applications for the designed antenna. The relative permittivity of more than 2.1 causes the existing working bands to change more or improve reflection loss. The measured results of paint impacts portray that the impact of radome paint has little change on the exhibition of the antenna and can make the designed antenna reasonable for bandwidth reconfigurable vehicular band communication applications.
Electricity and Electronic Devices
Published in David M. Scott, Industrial Process Sensors, 2018
The phototransistor (Figure 5.6) relies on light, rather than electrical current, to cause conduction. Its design includes an optical window that allows light to strike the base; the photoelectric effect creates charge carriers in the base region, so the amount of current flowing through the collector is proportional to the amount of light striking the phototransistor. A similar device is the PIN photodiode, which is a sandwich of p-type semiconductor, intrinsic semiconductor (with no free charge carriers), and n-type semiconductor. The PIN diode is normally reverse biased, so no current flows through the diode until light reaches the depletion zone that extends throughout the intrinsic layer. These devices are both used as optical detectors.
Radiation Pattern Agility of Printed Antennas
Published in Binod Kumar Kanaujia, Surendra Kumar Gupta, Jugul Kishor, Deepak Gangwar, Printed Antennas, 2020
Amit Bage, Surendra Kumar Gupta
A PIN diode is a P–N junction semiconductor diode in which an intrinsic layer of high resistivity is sandwiched between the P and N regions. At microwave and millimeter-wave, the diode operates as a variable resistor. It is most popular in microwave circuit applications due to its low radio frequency (RF) loss, variation of junction capacitance with reverse bias voltages, high power handling capability and fast switching time [21]. The construction and the symbolic representation of PIN diodes are shown in Figure 3.1a and b.
Design and analysis of double-layer parasitic split-ring resonator based on O-shaped engraved microstrip based radiating structure for 5G, WiMAX, WLAN and LTE applications
Published in Waves in Random and Complex Media, 2023
Sunil P. Lavadiya, M. M. Kamruzzaman, T. Senthil Kumar, Beulah Jackson, Shobhit K. Patel
In the proposed paper, we are mainly concentrating on frequency reconfigurability. Frequency reconfigurability depends on the structure’s electrical length; by changing the electrical length, the resonance frequency has deviated, and reconfigurability is achieved [3,11]. There are four methods available to achieve this. First is using switches like PIN diode, field-effect transistors, optical switches, and RF-MEMS that switch the operating frequency. The second method is variable reactive loading in that smoothly switching between different frequency bands is possible. The third method is effective dimension change by mechanical structure changes in that the magnetic actuator and piezoelectric actuator help to switch broad frequency bands. The fourth is a material change in that changing material deviates permeability and permittivity that differs the resonance frequency. Overall electrical and mechanical antenna structures require complex designs that reduce the radiation effect due to the parasitic impact [12]. Article [12] represents the method to achieve low dielectric loss and better tunability. The ferromagnetic material of barium strontium titanate (BST) varactor is useful for the miniaturized antenna, microwave devices, and reconfigurable antennas. The mechanism of the PIN diode is controlled by applying proper bias voltage on it to make it ON (short circuit) and OFF (open circuit). Similarly, the switching mechanism for connecting and disconnecting specific parts of the structure is always challenging because of rapid switching.
Hexa-band pattern reconfigurable antenna with defected ground plane
Published in International Journal of Electronics, 2021
Ghanshyam Singh, Binod Kumar Kanaujia, Vijay Kumar Pandey, Deepak Gangwar, Sachin Kumar
The fabricated antenna measurements are performed using Agilent PNA-L N5230A network analyser. To limit the effect of diode on the antenna radiation, SMP1345 series RF PIN diodes are employed for reshaping the prospective antenna attributes. When the series diode is forward biased (ON state), it offers very low resistance (1.5 Ω) in conjunction with packaging inductance of 0.45 nH. During OFF state (reverse biased), it offers very high resistance of 500 KΩ and a parallel capacitance of 0.2 pF in conjunction with packaging inductance of 0.45 nH. 20 pF DC blocking capacitance and 15 nH RF choke inductor are employed to segregate DC and RF supply lines. Miniaturised DC supply lines are constructed to mitigate the effect on impedance matching attributes. In the prospective model, the supply wires are made perpendicular to the main radiator to mitigate the impact of the bias line on antenna functioning. Tiny pads of 1 mm × 1 mm metals are fabricated for DC supply connection. The PIN diode (SMP1345-040LF) shows a very low insertion loss of 0.4 dB and consumes little power in the ON state for both near-field and far-field. Also, the diode shows high linearity over the operating frequency. As compared to the other switching devices, the PIN diode has many advantages such as small size, high switching speed, low distortion, low insertion loss, and good isolation with low power handling. Also, the reconfigurable antennas using PIN diode switches are simpler to fabricate. Compared to RF MEMS switches and FETs, PIN diodes have acceptable performance, low price, and a higher figure-of-merit.
Design and realization of frequency and mode electronically reconfigurable metamaterial stopband filter for wireless communication systems
Published in Electromagnetics, 2022
Hichem Boubakar, Mehadji Abri, Mohamed Benaissa, Sarosh Ahmad, Adnan Ghaffar
This section aims to present an electronically reconfigurable SBF (Figure 5). The reconfigurability is accomplished by loading PIN diodes on the triple-mode stopband filter designed in the previous section. The two characteristics that are controlled and change depending on the state of the filter are the resonant frequency and the mode of functioning (single, dual, or triple). The PIN diode acts as a current-controlled resistor for microwave and radiofrequency systems. It has two states, which are controlled by the bias voltage. The first provides low impedance and occurs when the polarization is direct. The second occurs when the polarization is in the opposite direction, providing high impedance and low capacitance (Watertown 1992).