The increasing demand for multifunctional devices, the use of cognitive wireless technology to solve the frequency resource shortage problem, as well as the capabilities and operational flexibility necessary to meet ever-changing environment result in an urgent need of multiband wireless communications. Spectral filter is an essential part of any communication systems, and in the case of multib...

The principle of recursive filters is well known in digital filtering. This paper deals with active recursive filters. A new design approach is presented. It will be shown that how active elements can be used in the design of amplification elements and large microwave time delay. The analytical and computer-simulated results will be presented for an active bandpass filter in the C-band. Key-Wor...

This paper introduces a new approach to design low pass microwave filter using impulse invariant transform. In this approach, the analog specifications of desired low pass filter is transformed into the digital specification and then apply an optimization technique (DSP based) to get an approximate transfer function in digital domain. Further, the transfer function in continuous time domain is ...

Abstract—The aliasing signal interferes with the actual signal and resembles more-like the original intermediate signal. This is called image frequency. To eliminate this image frequency a filter is to be designed in the RF(Radio Front) stage. At S-band microwave frequency (2 GHz to 4 GHz), the lumped components cannot be used due to distributed effects. Also, for the compactness of the filter,...

Reconfigurable microwave filters make microwave transceivers adaptable to multiple bands of operation using a single filter, which is highly desirable in today’s communications with evermore growing wireless applications. Tunable filters can replace the necessity of switching between several filters to have more than one filter response by introducing tuning elements embedded into a filter topo...

A survey of the major techniques used in the design of microwave filters is presented in this paper. It is shown that the basis for much fundamental microwave filter theory lies in the realm of lumped-element filters, which indeed are actually used directly for many applications at microwave frequencies as high as 18 GHz. Many types of microwave filters are discussed with the object of pointing...

Abstract A compact microwave parallel coupled line resonator seventh order bandpass filter (BPF) is presented in this paper, consist a 8-parallel coupled line pairs designed for a maximally flat response or Butterworth response at a center frequency of 2.44175 GHz and with a fractional bandwidth, ∆= 0.035. The filter was implemented in a microstrip platform with a permittivity of the substrate ...

An ultra-wideband (UWB) microstrip filter with a fractional bandwidth (FBW) of more than 100% is designed and demonstrated. This UWB microstrip-filter design is based on a circuit model for an optimum short-circuited stub transmission-line filter whose unit Figure 4 Reflection coefficient of the ultra-thin absorber: (a) simulated reflection coefficient; (b) measured reflection coefficient; (c) ...