Compact microstrip low pass filter design using U‐shaped folded high‐impedance line

Abstract

A microstrip low pass filter using a U‐shaped folded high impedance line is designed. Comparison with conventional filter has shown almost ripple free pass band and better stop band characteristics in the filter with folded line. Effective optimization of filter dimensions led to smoother and spurious free responses, which are desirable in the radio frequency and microwave systems. Size of overall filter is reduced by 7.5% and 9.02% for third order and fifth order filters, respectively. Both simulated and measured responses of fifth order filter are presented and found in agreement.

Modified Wilkinson power divider with harmonics suppression and compact size for GSM applications

“…According to Table 1, the −3 dB cut‐off frequency of the proposed LPF is 2.8 GHz. The proposed LPF has a sharp ROF in comparison with the published works in References 4–9. The stop bandwidth is wide and equal to 7.49 GHz (3.41‐10.9 GHz).…”

“…The stop bandwidth is wide and equal to 7.49 GHz (3.41‐10.9 GHz). Moreover, the attenuation level in the stopband is 20 dB, indicating the SF parameter is highest in comparison with the proposed one in References 4–8. The layout and fabricated sample of the proposed modified Wilkinson power divider are illustrated in Figure 7.…”

“…Radio frequency (RF)/microwave power dividers with good properties such as wide stopband, compact size, high suppression factor (SF), high isolation between output ports, and simple structure are widely used in modern wireless communication systems for dividing the input signal into two or more signals. Nowadays, filters 1–10 and power dividers 11–25 are widely used in microwave systems such as power amplifiers, mixers, and feeding network in an antenna array, because they are easily designed and fabricated with other microwave devices. In Reference 1, a compact low‐pass filter (LPF) with wide stopband using stepped impedance and open stubs is presented.…”

“…An LPF with multi open‐circuited shunt stubs is reported in Reference 4. A microstrip LPF using a U‐shaped folded high impedance line is designed in Reference 5, and a LPF using defected ground structure (DGS) is presented in References 6 and 9, but the ROF parameter is low. A compact LPF proposed in Reference 7 using a T‐shaped resonator and results show low IL in the passband and wide stopband.…”

Wide Band Stop Response Using Interdigital Capacitor/CSRR DGS in Elliptical Microstrip Low-Pass Filter

“…In order to address the compactness of filter, top layer is modified by inserting a U-shaped highimpedance line in place of the straight line as reported in [5]. is observed for HL-ELPF with mitered U-shaped line, which is shown in Figure 10 The characteristics of low-pass filter designs reported in this work are summarized in Table II as discussed in this section and previous section.…”