Dispersive delay structure using cascaded‐coupled CRLH‐CRLH C‐sections

Abstract

The demand for analog signal processing (ASP) is rising for high-speed and highfrequency systems. In some ASP systems, the core is dispersive delay structure (DDS). DDS creates a steady increase or decrease in group delay over frequency bandwidth. One of the popular methods for designing DDSs is the use of coupled C-sections structure. Analysis of the coupled C-sections was based on the analysis of N coupled-lines network. In this paper, we employ a fast approach for analyzing N coupled-lines network that does not need solving an eigenmodes problem. Moreover, we propose a novel DDS structure based on the coupled composite right/lefthanded (CRLH) transmission lines with interdigital capacitors and short stub inductors. The proposed DDS operates between 3 to 3.5 GHz with relatively high group delay slope (about 5.5 ns). The measurements are presented for scattering parameters and group delay to compare with simulated results. K E Y W O R D SCRLH, C-section, DDS, dispersive delay structure, group delay, metamaterial

Frequency generator demonstration using half mode Substrate Integrated Waveguide (SIW) structures for chipless Radio Frequency Identification (RFID) reader

“…The backward coupling supports the TEM wave propagation and is suitable for low-frequency applications. The forward coupling, which works for a non-TEM environment is SHARMA AND HASHMI used as a waveguide, and is appropriate for high-frequency applications and can also be used as a transmission line [22,25]. Figure 2 depicts a typical signal flow graph for a fourport forward coupler.…”

“…However, these oscillators often suffer from large size and design complexity and cannot be tuned continuously. However, these issues can be overcome by Transverse Electromagnetic (TEM) C-section structures [22]. But C-section structures are difficult to realise at higher frequencies due to large coupling while achieving more substantial dispersion.…”

Substrate integrated waveguide dispersive delay structure based on wave trapping

“…Generally, the size and the loss of the structure still is an issue compared to some other passive DDSs [11, 13]. Also, the bandwidth of the proposed structure is limited due to periodicity.…”

“…However, passing wave through a single dispersive TL like a waveguide [9] or a composite right/left‐handed (CRLH) line [10, 11] is a practical and straightforward way to obtain a dispersion. Combining these two methods (dispersive configuration and TLs) could lead to a compact DDS and a high group delay value [12, 13].…”