scholarly journals Analysis of RF Front-End Performance of Reconfigurable Antennas with RF Switches in the Far Field

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Insu Yeom ◽  
Junghan Choi ◽  
Sung-su Kwoun ◽  
Byungje Lee ◽  
Changwon Jung
Keyword(s):  
Mobile Devices ◽  
Field Condition ◽  
Rf Mems ◽  
Reconfigurable Antennas ◽  
Reconfigurable Antenna ◽  
Far Field ◽  
Rf Switches ◽  
Mems Switches ◽  
Front End ◽  
Rf Front End

The RF front-end performances in the far-field condition of reconfigurable antennas employing two commonly used RF switching devices (PIN diodes and RF-MEMS switches) were compared. Two types of antennas (monopole and slot) representing general direct/coupled feed types were used for the reconfigurable antennas to compare the excited RF power to the RF switches by the reconfigurable antenna types. For the switching operation of the antennas, a biasing circuit was designed and embedded in the same antenna board, which included a battery to emphasize the antenna’s adaptability to mobile devices. The measurement results of each reconfigurable antenna (radiation patterns and return losses) are presented in this study. The receiving power of the reference antenna was measured by varying the transmitting power of the reconfigurable antennas in the far-field condition. The receiving power was analyzed using the “Friis transmission equation” and compared for two switching elements. Based on the results of these measurements and comparisons, we discuss what constitutes an appropriate switch device and antenna type for reconfigurable antennas of mobile devices in the far-field condition.

RF MEMS for Reconfigurable RF Front-End: Research in Australia

2014 ◽  
Vol 901 ◽  
pp. 105-110 ◽  
Author(s):  
Liang Gong ◽  
King Yuk Chan ◽  
Yi Yang ◽  
Rodica Ramer
Keyword(s):  
Rf Mems ◽  
Mems Switches ◽  
The Past ◽  
Front End ◽  
Rf Front End ◽  
Rf Mems Switches ◽  
Mems Technology ◽  
Front End Circuits ◽  
Rf Performance ◽  
Reconfigurable Filters

This paper reviews some ground breaking development of RF MEMS technology in Australia at the UNSW, over the past decade. It presents some unique and novel designs using RF MEMS switches to achieve reconfigurable RF front-end circuits. These designs include multiport RF MEMS switches, switch matrices, reconfigurable filters and antennas. The resulting devices achieved RF performance that is unmatched by any existing RF andmicrowave technologies.

Ultra-low Residue Flux Applications in RF Front-End Packages

2020 ◽  
Vol 2020 (1) ◽  
pp. 000125-000130
Author(s):  
Leo Hu ◽  
Sze Pei Lim
Keyword(s):  
Integrated Circuits ◽  
Flip Chip ◽  
Low Noise ◽  
Low Noise Amplifiers ◽  
Reflow Process ◽  
Reliability Study ◽  
Rf Switches ◽  
Front End ◽  
Rf Front End ◽  
Package Reliability

Abstract With the leap into the 5G era, the demand for improvements in the performance of mobile phones is on the rise. This is also true for the quantity of radio frequency (RF) front-end integrated circuits (ICs), especially for RF switches and low noise amplifiers (LNA). It is well-known that improvements in performance depend on the combination of new design, package technology, and choice of materials. Ultra-low residue (ULR) flux is an innovative, truly no-clean, flip-chip bonding material. By using ULR flux, the typical water-wash cleaning process can be removed and, in some instances, package reliability can be improved as well. This simplified assembly process will help to reduce total packaging costs. This paper will discuss the application of ULR fluxes on land grid arrays (LGAs) and quad-flat no-leads/dual-flat no-leads (QFN/DFN) packages for RF front-end ICs, as well as the reflow process. The solder joint strength and reliability study will be shared as well.

A Novel Piezoelectric RF-MEMS Resonator with Enhanced Quality Factor

2022 ◽  
Author(s):  
JINCHAO LI ◽  
Zeji Chen ◽  
Wenli Liu ◽  
Jinling Yang ◽  
Yinfang Zhu ◽  
...  
Keyword(s):  
Elastic Waves ◽  
High Frequency ◽  
Rf Mems ◽  
Comprehensive Analysis ◽  
Quality Factors ◽  
Piezoelectric Resonator ◽  
Front End ◽  
Rf Front End ◽  
Mems Resonator ◽  
Compact Size

Abstract This work presents a novel ultra-high frequency (UHF) Lamb mode Aluminum Nitride (AlN) piezoelectric resonator with enhanced quality factors (Q). With slots introduced in the vicinity of the tether support end, the elastic waves leaking from the tether sidewalls can be reflected, which effectively reduces the anchor loss while retaining size compactness and mechanical robustness. Comprehensive analysis was carried out to provide helpful guidance for obtaining optimal slot designs. For various resonators with frequencies ranging from 630 MHz to 1.97 GHz, promising Q enhancements up to 2 times have all been achieved. The 1.97 GHz resonator implemented excellent f × Q product up to 6.72 × 1012 and low motional resistance down to 340 Ω, which is one of the highest performances among the reported devices. The devices with enhanced Q values as well as compact size could have potential application in advanced RF front end transceivers.

scholarly journals Modular Design of RF Front End for a Nanosatellite Communication Subsystem Tile Using Low-Cost Commercial Components

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Haider Ali ◽  
Anwar Ali ◽  
M. Rizwan Mughal ◽  
Leonardo Reyneri ◽  
Claudio Sansoe ◽  
...  
Keyword(s):  
Modular Design ◽  
Low Cost ◽  
Ground Plane ◽  
Low Noise ◽  
Space Environment ◽  
Radio Communication ◽  
Matching Network ◽  
Rf Switches ◽  
Front End ◽  
Rf Front End

In recent years, the development market for low-cost nanosatellites has grown considerably. It has been made possible due to the availability of low-cost launch vectors and the use of “commercial off-the-shelf components” (COTS). The satellite design standardization has also helped a great deal to encourage subsystem reuse over a number of space missions. This has created numerous opportunities for small companies and universities to develop their own nanosatellite or satellite subsystems. Most COTS components are usually not space qualified. In order to make them work and withstand the harsh space environment, they need extra effort in circuit redesign and implementation. Also, by adopting the modularity concept and the design reuse method, the overall testing and nonrecurring development cost can be significantly reduced. This can also help minimize the subsystem testing times. The RF front-end design presented in this paper is also considered one of the better and feasible choices based on the above approach. It consists of an S-band transceiver that is fully implemented using COTS components. In the transmit chain, it is comprised of the transmitting CC2510 RF matching network and a power amplifier (PA) with an RF output power of up to 33 dBm which connects to an antenna using two RF switches. The receive chain starts from the antenna that is connected through two RF switches to the low-noise amplifier (LNA) that further connects to the receiving CC2510 via the RF matching network. The receiver sensitivity is -100 dBm. This is a half-duplex system using the same antenna for transmitting and receiving. The receiver and transmitter chains are isolated together using two RF switches which together provide an isolation of up to 90 dB at 2.4 GHz. The concept behind using two RF switches is to provide better isolation from the transmit chain to the LNA. The matching network of CC2510 has been designed in a symmetric fashion to avoid any delays. All the RF COTS used have been selected according to link budget requirements. The LNA, PA, and RF switches were tested individually for compliance. The passive components used in the overall design of the matching network are chosen on the basis of minimum dimension, least parasitic behaviour, and guaranteed optimum RF matching. Also, the RF COTS used are non-CMOS which makes them more robust against space radiations associated with the LEO environment and enables them to provide a radio communication data rate of up to 500 kbps in both uplink and downlink. The vacant spaces on the implemented PCB are shielded with a partial ground plane to avoid RF interference.

scholarly journals Reconfigurable Antenna using Micromechanical Actuation Switches for K and Ku-Band Applications

2019 ◽  
Vol 9 (2) ◽  
pp. 201-205
Keyword(s):  
Insertion Loss ◽  
Patch Antenna ◽  
Rf Mems ◽  
Reconfigurable Antenna ◽  
Resonant Frequencies ◽  
Mems Switches ◽  
Actuation Mechanism ◽  
Rf Mems Switches ◽  
Mechanical Actuation ◽  
Ku Band

In this paper, we have proposed a reconfigurable antenna using micro mechanical actuation switches for K and Ku-band applications. Overall two identical cantilever micro mechanical switches (S1 & S2 ) are used to design reconfigurable patch antenna. The switches are working by electrostatic actuation mechanism. With the switches, overall the antenna is offering four resonant frequencies based on the switches ON/OFF condition. The Micro mechanical switches are offering an isolation loss of -18.5dB and an insertion loss of -1dB. The switch requires a DC actuation voltages of 6V. The Proposed reconfigurable antenna is resonating at four different frequencies based on the different switching conditions of RF MEMS switches. If S1 & S2 both are ON the antenna is resonating at 16.9GHZ, if S1 -ON & S2 -OFF the antenna is resonating at 47.3GHZ & 59.1GHZ, if S1 -OFF & S2 -ON the antenna is resonating at 28.4GHZ, if S1 -OFF & S2 -OFF the antenna is resonating at 27.9GHZ

Micro/Nanotribology of RF MEMS Switches

2004 ◽  
Author(s):  
Steven T. Patton ◽  
Kalathil C. Eapen ◽  
Jeffrey S. Zabinski
Keyword(s):  
Electric Current ◽  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Low Cost ◽  
Operating Conditions ◽  
Great Promise ◽  
Rf Switches ◽  
Mems Switches ◽  
Adhesion Contact ◽  
Rf Mems Switches

Microelectromechanical systems (MEMS) radio frequency (RF) switches hold great promise in a myriad of commercial, aerospace, and military applications. MEMS switches offer important advantages over current electromechanical and solid state technologies including high linearity, low insertion loss, low power consumption, good isolation, and low cost [1–21]. However, there is little fundamental understanding of the factors determining the performance and reliability of these devices. Our previous work investigated fundamentals of hot-switched direct current (DC) gold (Au) contacts using a modified microadhesion apparatus as a switch simulator [1]. Those experiments were conducted under precisely controlled operating conditions in air at MEMS-scale forces with an emphasis on the role of surface forces and electric current on switch performance, reliability, and durability [1]. Electric current had a profound effect on deformation mechanisms, adhesion, contact resistance (R), and reliability/durability. At low current (1–10 μA), asperity creep and switching induced adhesion were the most important observations, whereas, at high current (1–10 mA), lack of adhesion and switch shorting by nanowire formation were prominent [1].

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