Synthesis of 8th order Active-Band pass filter for UHF Radio Frequency Identification System using MFB Topology

International Journal of Research and Scientific Innovation (IJRSI) | Volume VIII, Issue III, March 2021 | ISSN 2321–2705

Synthesis of 8th order Active-Band pass filter for UHF Radio Frequency Identification System using MFB Topology

Atsuwe, B.A.¹, Amah, A. N.² and Igwue, G.A.^3
1Department of Science Education, University of Agriculture, Makurdi-Nigeria
²Department of Physics, University of Agriculture, Makurdi-Nigeria
³Department of Electrical/Electronics, University of Agriculture, Makurdi-Nigeria

Abstract: This paper presents the design and simulation of eight order Active Band pass filter for UHF Radio Frequency Identification System (RFID) using the multiple Feedback Topology and the gain magnitude response is simulated using MULTISIM work bench version 11.0. the result shows that the filter has a mid-band frequency that decreases from f0=40KHz (106.505dB) to f0=256KHz (87.908dB) and increases again from f0=320KHz (88.449dB) to 640KHz (95.085dB), while the Bandwidth increased from 0.959KHz to 21.537KHz (ff0=40KHz to f0=320KHz) and then decreases from 25.376KHz to 25.162KHz (f0=465KHz to f0=640KHz). The roll-off rate behaves like a single filter with values approaching -60dB/decade instead of a double stage filter. These however conform with the specifications of EPC class one Generation 2 Standard for UHF domain RFID which offer new opportunities to develop RFID systems for better performance. Therefore the filter can be used for RFID systems.

Key words: Eighth-Order, Active-Band Pass, filter, Ultra High Frequency (UHF) RFID, Multiple Feedback.

I. INTRODUCTION

In the reader, the front-end system needs RC filter and Active Band pass filter and an Active low-pass filter to reject the undesired signal (Zin, and Zaw, 2009). Filters are essential components in the many electrical systems.
In the state-of-the-art RF receivers, high performance filters are required to remove undesired signals at different stages of the receiving process, such as noise from incoming signals the antenna receives undesired signals at the image frequency, and harmonics after the mixing operation (Zin et al., 2009).
In the UHF RFID system, Active filters are used because of the following advantages (Sridevi, 2001;Löwenborg, 1999);
1. The transfer function with inductive characteristics can be achieved by particular circuit design, resistors can be used instead of inductors.
2. The high input impendence and low output impendence of the operational amplifier means that the filter circuit is excellent in isolation characteristics and suitable for cascade.
3. Active components provides amplification, therefore active filters have high gains.
The active filter without the capacitor is called and Active-R filter and has received much attention due to its potential advantages in terms of miniaturization, ease of design and high frequency performance [Srinivasan, (1992); Shinde, Patil, and Mirkute, (2003)]. Also Active-R filter offer substantially low sensitivity characteristics as compared to R-C structure (Soderstand and Mitra, 1971).
Active-R filters give greater stop band attenuation and sharper roll-off at the edge of the pass band. Also in terms of functionality the Active-R filter is better than the Active-RC (Igwe, Amah, and Atsuwe, 2014).

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