Design and Manufacturing of a Novel Compact 2.4 GHZ LPF Using a DGS-DMS Combination and Quasi Octagonal Resonators for Radar and GPS Applications

Abstract

In this paper, a new compact microstrip low-pass filter (LPF) with ultra-wide stopband characteristics is presented. The combinations of DGS-DMS along with quasi octagonal resonators are employed in the design of the proposed filter to achieve compact size and ultra-wide stopband suppression level. The proposed filter has been designed, simulated, optimized and tested. The design procedure is validated using the commercial full-wave EM MoM simulator Microwave Office. Simulated as well as measured results of low-pass filter exhibit sharp roll-off (ξ) of 19 dB/GHz and creating transmission zero at around 7.8 GHz with attenuation level −54 dB. The measurement results show good agreement with the simulations. The cutoff frequency of the proposed low-pass filter is 2.4 GHz with the insertion loss less than 0.3 dB. The ultra wide stopband with over 20 dB attenuation extended from 3.42 GHz to 12 GHz. The spurious passband suppression up to six harmonics (5f c) is achieved for the proposed design. The addition of two parasitics DGS elements in the ground plane leads to suppression of the undesired harmonics und thus to improve the stopband. The size of the whole structure is less as (0.44λ g × 0.26λ g) with λ g = 68 mm. The proposed filter is useful for microwave L band, GPS system, and RADAR applications.

Design of a compact reconfigurable bandpass filter using interdigital capacitor, DMS slots and varactor diode for wireless RF systems

“…The resonance frequency 𝑓 0 can be expressed using the following equation [1]: To make the filter resonating at 2.4 GHz, a lumped capacitor 𝐶 𝑣 of 1.15 pF in parallel with 𝐶 gap is integrated as illustrated in figure 3. The resonant frequency is then calculated using equation (7) with 𝐶 𝑣 + 𝐶 gap instead of 𝐶 𝑣 . Its impact on S parameters is presented in figure 4.…”

“…Compact planar filter structures have become increasingly reliable over the past few years. Several manufacturing processes for tunable compact filters are presented in the literature such as stepped-impedance resonator filter design [3], parallel coupled line filter [4,5], ring resonator filter design [6], filter designed on a defect ground structure [7] and open loop resonator filter design [8,9].…”

Second order microstrip bandpass filter design based on square resonator for 5G sub-6 GHz band

“…In this work, the mid-band called sub-6 GHz (3.5 GHz to 3.8 GHz) is adopted, which is available in several communication systems in Europe, America and Asia [1][2][3][4]. In these communication systems, many electronic devices are connected together to generate and receive radio signals for specific operational frequency and band frequency [5][6][7][8][9][10][11][12]. In order to capture the specific operational frequency, the microwave filter is the key component for separating unwanted frequencies.…”

Design of compact microstrip bandpass filter using square DMS slots for Wi-Fi and bluetooth applications

“…This change affects the resonance characteristics in the frequency response. However, these characteristics can be used to design compact microwave components [18][19][20][21][22][23].…”