scholarly journals A Mode Decoupling Method for Circular Patch Antennas

2021 ◽  
Vol 2015 (1) ◽  
pp. 012140
Author(s):  
M. Siganov ◽  
S. Glybovski ◽  
D. Tatarnikov

Abstract In this contribution, we investigate the effect of mode decoupling for dual-feed circular patch antennas. We consider an antenna comprising a circular disc patch placed inside an annular-ring patch. Both patches are resonant radiators, which can be fed by two different vertical posts. Due to the field interaction of the patches, the feeds experience parasitic cross-talk limiting the receive diversity performance of the system. Here, we demonstrate the possibility to suppress the cross-talk at the operational frequency by including a capacitive decoupling element into the circular patch. The physical mechanism of the method consists in the excitation of two different eigenmodes (TM01 and TM11) in a certain combination canceling the mutual coupling. The presented decoupling method can be used for patches operating either at the same frequency or at two different frequencies. In the proposed dual-feed antenna it is possible to achieve an isolation level of better than -45 dB. In contrast to the method of decoupling and matching network used for the same type of antennas, one does not need couplers to feed the patches, which reduces losses.

Author(s):  
Minal Kimmatkar ◽  
P. T. Karule ◽  
P. L. Zade ◽  
P. S. Ashtankar

In this paper, Ultra wideband planar circular patch and half circular ring patch antennas are proposed. These newly simulated structures are proposed for fabrication. The antennas are suitable for operating frequency of 7.5 GHz. It is shown that return loss of the both the antennas at 7.5 GHz is better than -10 dB. The VSWR obtained is less than 2. The half ring patch antenna is found to have the compact size and more bandwidth as that of circular patch antenna. HFSS11 is used for the simulation. From HFSS11 simulations, dimensions of antennas are chosen for better performance. Details of the proposed antenna design and measured results are presented in this paper


2020 ◽  
Vol 3 (4) ◽  
pp. 42
Author(s):  
Albert Sabban

The development of compact passive and active wearable circular patch metamaterials antennas for communication, Internet of Things (IoT) and biomedical systems is presented in this paper. Development of compact efficient low-cost wearable antennas are one of the most significant challenges in development of wearable communication, IoT and medical systems. Moreover, the advantage of an integrated compact low-cost feed network is attained by integrating the antenna feed network with the antennas on the same printed board. The efficiency of communication systems may be increased by using efficient passive and active antennas. The system dynamic range may be improved by connecting amplifiers to the printed antenna feed line. Design, design considerations, computed and measured results of wearable circular patch meta-materials antennas with high efficiency for 5G, IoT and biomedical applications are presented in this paper. The circular patch antennas electrical parameters on the human body were analyzed by using commercial full-wave software. The circular patch metamaterial wearable antennas are compact and flexible. The directivity and gain of the antennas with Circular Split-Ring Resonators (CSRR) is higher by 2.5dB to 3dB than the antennas without CSRR. The resonant frequency of the antennas without CSRR is higher by 6% to 9% than the antennas with CSRR. The computed and measured bandwidth of the stacked circular patch wearable antenna with CSRR for IoT and medical applications is around 12%, for S11 lover than −6dB. The gain of the circular patch wearable antenna with CSRR is around 8dBi.


2007 ◽  
Vol 73 (18) ◽  
pp. 5711-5715 ◽  
Author(s):  
Sung Kuk Lee ◽  
Howard H. Chou ◽  
Brian F. Pfleger ◽  
Jack D. Newman ◽  
Yasuo Yoshikuni ◽  
...  

ABSTRACT Synthetic biological systems often require multiple, independently inducible promoters in order to control the expression levels of several genes; however, cross talk between the promoters limits this ability. Here, we demonstrate the directed evolution of AraC to construct an arabinose-inducible (PBAD) system that is more compatible with IPTG (isopropyl-β-d-1-thiogalactopyranoside) induction of a lactose-inducible (Plac) system. The constructed system is 10 times more sensitive to arabinose and tolerates IPTG significantly better than the wild type. Detailed studies indicate that the AraC dimerization domain and C terminus are important for the increased sensitivity of AraC to arabinose.


1991 ◽  
Vol 27 (6) ◽  
pp. 532 ◽  
Author(s):  
R.Q. Lee ◽  
T. Talty ◽  
K.F. Lee

2012 ◽  
Vol 11 ◽  
pp. 389-391 ◽  
Author(s):  
Xin Mi Yang ◽  
Xue Guan Liu ◽  
Xiao Yang Zhou ◽  
Tie Jun Cui

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