Miniaturised dual‐band filter with high selectivity using split ring scheme

Abstract

A novel miniaturised dual-band bandpass filter (BPF) using improved split ring λ/4 resonator and stepped impedance resonator (SIR) is proposed. A simple analysis is given for each resonator. By tuning the geometric parameters of the resonators, the two passbands of the BPF can be adjusted separately. Source-load coupling is adopted to achieve more transmission zeros in the stopband. The new dual-band BPF, which has a miniature circuit size of 0.18 × 0.18λg, presents narrow and sharp passband characteristics. Good agreement is found between simulated and measured results, which verify the high-frequency selectivity.

Design of 5 GHz‐compact reconfigurable DGS‐bandpass filter using varactor‐diode device and coupling matrix technique

“…In particular, the linearity of the power amplifier becomes increasingly important to guarantee the high data rate of the sophisticated modern wireless communication systems [1][2][3]. However, as shown in Figure 1, owing to the trade-off relationship between the power efficiency and the linearity of power amplifiers, it becomes difficult to obtain reasonable efficiency with the required linearity in the power amplifier [6][7][8]. Accordingly, various efficiency enhancement techniques for power amplifiers have been studied vigorously [9][10][11][12][13][14][15].…”

“…With the development of wireless communication, the more crowded the spectrum is, the more stringent specifications for designing filters are. The repaid growth of the wireless communication systems require designing compact and multiband microwave bandpass filters [1][2][3][4][5][6][7][8]. Therefore, these systems require multiband operating transceivers.…”

Compact Band-Pass Filter with Controllable Frequency Characteristics

“…The evolution of 4G cellular systems towards the first 5G milestone is increasingly creating the need for the design of compact and multiband microwave bandpass filters [1][2] that can provide RF connectivity within a multimode wireless networking environment. Planar filters are attractive due to their reduced size, ease of fabrication, and offering lower cost.…”

Compact semi‐lumped dual‐ and tri‐wideband bandpass filters

“…Multi-band bandpass filters (BPFs) are essential components in modern multi-service communication system. So far, many structures or approaches are developed to design multi-band BPFs such as half-mode substrate integrated waveguide with slot perturbation in [1], ring resonator in [2], ring resonator and tightly coupled input and output structures in [3], coupled lines multimode resonator in [4], multiple stubs loaded ring resonator in [5], patch resonator in [6], stub loaded stepped impedance resonator (SIR) in [7,8], multipath-embedded SIR in [9], and eight-mode resonator in [10]. However, these reported dual-band bandpass filters [1][2][3][4][5][6] and tri-band bandpass filters (TB-BPFs) [5,[7][8][9][10] have relative narrow bandwidth which cannot meet the requirement of recent high data-rate communication technology.…”