A Convenient Designing Method of Feed Network at Low Frequency - The Substructure Method

2010 ◽  
Vol 29-32 ◽  
pp. 884-889
Author(s):  
Hua Wei Zhan ◽  
Cai Xia Guo ◽  
Yu Zhang ◽  
Yun Zhou

Multimode feed network is an important part of shortwave multimode multifeed antenna system. The design of feed network is a pivotal technique in the process of projecting antenna system. The substructure analyzing method of interconnect-net is based on the substructure matrix database which is formed by converting the net parameters into data. And it characterizes the non-uniform net units through the database directly. Then cascades the known database of the net units by means of ordinary net cascade method, thus performing optimization in the net. In the paper, the Substructure Analyzing Method of Interconnect-net is applied to designing multi-mode multi-feed network, a typical example of multi-mode multi-feed network optimization is given to illustrate the efficiency of the method.

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2931
Author(s):  
Waldemar Jendernalik ◽  
Jacek Jakusz ◽  
Grzegorz Blakiewicz

Buffer-based CMOS filters are maximally simplified circuits containing as few transistors as possible. Their applications, among others, include nano to micro watt biomedical sensors that process physiological signals of frequencies from 0.01 Hz to about 3 kHz. The order of a buffer-based filter is not greater than two. Hence, to obtain higher-order filters, a cascade of second-order filters is constructed. In this paper, a more general method for buffer-based filter synthesis is developed and presented. The method uses RLC ladder prototypes to obtain filters of arbitrary orders. In addition, a set of novel circuit solutions with ultra-low voltage and power are proposed. The introduced circuits were synthesized and simulated using 180-nm CMOS technology of X-FAB. One of the designed circuits is a fourth-order, low-pass filter that features: 100-Hz passband, 0.4-V supply voltage, power consumption of less than 5 nW, and dynamic range above 60 dB. Moreover, the total capacitance of the proposed filter (31 pF) is 25% lower compared to the structure synthesized using a conventional cascade method (40 pF).


2019 ◽  
Vol 230 (12) ◽  
pp. 4341-4356 ◽  
Author(s):  
Qichen Wu ◽  
Gangting Huang ◽  
Chong Liu ◽  
Shilin Xie ◽  
Minglong Xu

1980 ◽  
Vol 91 ◽  
pp. 403-403
Author(s):  
Ch. V. Sastry

Most observations of interplanetary scintillations of radio sources are made at frequencies around 80 MHz. These observations are limited to regions close to the sun, where the scintillations are maximum at this frequency. It is possible to extend these observations to the weakly scattering regions beyond 1 A.U. by making measurements at low frequencies. We have built a low frequency antenna system at Gauribidanur, India (Lat. 13° 36′ N and Long. 5 hrs. 10 min.), which can be used for this purpose. Although this system will not be dedicated to IPS, we intend to use it exclusively for solar wind observations during periods of interest.


2000 ◽  
Author(s):  
Gie H. Tan ◽  
Christof H. Rohner

Author(s):  
Kaiwalya Pethe ◽  
Shridhar Galande ◽  
Sachin Jamadar ◽  
S. P. Mahajan ◽  
R. A. Patil ◽  
...  

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