CSRR DGS-Based Bandpass Negative Group Delay Circuit Design

Abstract

The unfamiliar negative group delay (NGD) circuit is the less familiar function for most of RF and microwave design engineers. Among the existing types, the bandpass (BP) NGD type circuits are the most convenient for the wireless communication microwave technology. Therefore, it is particularly important to explore different microwave circuit topologies operating as BP-NGD function. An innovative design of BP-NGD topology constituted by defected ground structure (DGS) with complementary split ring resonator (CSRR) is developed in the present paper. The DGS-based BP-NGD structure design method is introduced in function of the CSRR geometrical elements followed by S-parameter parametric analyses. As proof-of concept (POC), the design method of the proposed BP-NGD passive fully distributed circuit is described. The effectiveness of the BP-NGD structure and the test feasibility are investigated by implementing two different prototypes represented by single-and double-wing DGS passive circuits. It is observed that significant BP-NGD function performances were validated by well-correlated simulations and measurements showing -1.9 ns NGD value around the center frequency, 2.46 GHz over 31 MHz NGD bandwidth. In addition, the tested BP-NGD prototypes present insertion loss better than 4 dB and reflection loss better than 16.7 dB. Because of its potential integration, the investigated BP-NGD circuit is potentially useful for the communication system performance improvement for example via delay effect reduction in the RF and microwave devices.INDEX TERMS Defected ground structure (DGS), design method, microwave circuit, bandpass negative group delay (BP-NGD) function, NGD analysis.

New Complementary Resonator for Permittivity- and Thickness-Based Dielectric Characterization

“…The MTL of the width a 1 = 2.192 mm is printed on the upper layer of the AD250C substrate of a square shape and size b 1 = 20 mm and b 2 = 20 mm, as shown in Figure 1a. The geometry of the CCAR is derived from the fundamental structure known as the complementary square split ring resonator (CSSRR), which has been used recently to design negative group delay circuit [18], substrate-integrated waveguide filter [19], wideband antenna [20], and microwave sensor [21]. Figure 2 shows the progression of the CCAR geometry from its predecessor, the CSSRR.…”

“…Initially, a CSSRR with the three geometric parameters (d 1 = 4 mm, d 2 = 3 mm and d 3 = 0.5 mm) is designed, as shown in Figure 2a. The initial geometric parameters were chosen by a comprehensive analysis of the existing literature [18][19][20][21]. After simulation, the CSSRR under investigation exhibits a resonant frequency of 8.6 GHz, accompanied by a notable notch depth of −26.7 dB.…”

Design of Miniaturized SIW Filter Loaded with Improved CSRR Structures

“…Different from a traditional CSRR Developments have highlighted CSRRs as excellent electromagnetic scatterers [16] that exhibit behavior similar to SRRs, generating stopbands when the CSRR resonator frequency is above the waveguide cutoff frequency and transforming into passbands when the CSRR resonator frequency is below the waveguide cutoff frequency [17][18][19][20]. As a result, CSRRs have found practical utility in designing various filters, including the balun filter, differential filter and negative group delay filter [21][22][23][24][25][26][27]. However, nearly all related research has focused on RF frequencies under 10 GHz [28][29][30][31], which do not meet the requirement under the development of millimeter-wave 5G communications.…”