Two-dimensional Electromagnetic Crystal Research Articles

A W-Band Low-Loss Dual-Polarization Quasi-TEM Waveguide

As an enabling feed/interconnect element for various millimeter wave components, dual polarization quasi-transverse electromagnetic (TEM) waveguides at W-band (75-110 GHz) are investigated with two-dimensional electromagnetic crystal (EMXT) surfaces as the four boundary walls instead of the regular metallic walls. A 2.54 mm x 2.54 mm quasi-TEM square waveguide prototype with a length of 2 mm is fabricated and demonstrated. Both eigenmode and full-wave EM simulations of the prototype verify the quasi-TEM propagation at the designed frequency of 95 GHz with a bandwidth of more than 10% and the low insertion loss for the entire W-band. The prototype waveguide is measured in a WR-10 fixture and the results agree with simulations well. To better understand the loss mechanisms, various design and packaging parameters are studied. Undesirable resonant surface modes have been identified as a critical cause of loss at specific frequencies. This type of waveguides may also be useful for spatial power combining, low loss interconnects, and packaging for millimeter wave systems.

Erratum: Two-dimensional electromagnetic crystals formed by reactively loaded wires [Phys. Rev. E66, 036610 (2002)

Erratum: Two-dimensional electromagnetic crystals formed by reactively loaded wires [Phys. Rev. E<b>66</b>, 036610 (2002)

Two-dimensional electromagnetic crystals formed by reactively loaded wires.

Two-dimensional electromagnetic crystals formed by rectangular lattices of thin ideally conducting cylinders periodically loaded by bulk reactive impedances are considered. An analytical theory of dispersion and reflection from this medium is presented. The consideration is based on the local field approach. The transcendental dispersion equation is obtained in the closed form and solved numerically. Different types of the loads such as inductive, capacitive, serial, and parallel LC circuits are considered. Typical dispersion curves and reflection coefficients are calculated and analyzed.

Wave channelling in compact multiport waveguides patterned in electromagnetic crystals

Routing functions are investigated through the use of compact waveguide structures inserted in two-dimensional electromagnetic crystals. Wave channelling is obtained in multibranch couplers whose geometries are carefully designed to promote both selective and directive transfer processes. A quality factor Q∼1100 (effective bandwidth: 0.09%) and a high directionality (∼25 dB) for a full transfer process in a compact design can be obtained through this mode engineering of the coupling zone. It is shown that the origin of the directivity is a symmetry break owing to the superposition of cavity modes. A three-colour demultiplexer based on such a design will be finally proposed.