Coplanar Line Structures Research Articles

Film bulk acoustic resonator filters with a coplanar waveguide

Multiple thin film bulk acoustic resonators (10, 11) configured in series (10) and parallel (11) within a coplanar waveguide line structure provides a compact ladder filter. The resonators (10, 11) are formed over an opening (28) in a substrate (20) and connected to associated circuitry by one or more transmission lines formed on the substrate (20). The arrangement of the resonators (10, 11) between the ground and signal lines of a coplanar line structure provides a means of minimising the area of the filter. Embedding a ladder filter within the coplanar transmission line structure eliminates the need for wire bonds, thus simplifying fabrication. Embodiments for 2×2, and hither order filters are described.

Yb and Ca Doped Ba0.6Sr0.4TiO3 for device application near room temperature

The effects of doping Ba0.6Sr0.4TiO3 with CaO3, CaCO3 and Yb2O3 on bulk dielectric constants and the loss tangent are presented as a function of voltage and temperature. The use of these materials for microwave devices has been limited by loss both in the material and in the metal used to form the capacitors and delay lines in thin-film coplanar line structure. One sample of BST doped 5% Yb2O3 has been measured to have the lowest loss tangent we have observed for this class of materials with tan δ < 0.002 at temperature just above the Curie temperature of 280°K. The estimated relative dielectric constant at zero volts was approximately 14000. The reproducibility of these values is strongly dependent on the material processing parameters including firing temperatures and oxygen content.

A coplanar transmission line high-T/sub c/ superconductive oscillator at 6.5 GHz on a single substrate

The design and construction of a planar, low-noise cryogenic oscillator operating at 6.5 GHz are presented. The oscillator has been built as a hybrid superconductive microwave integrated circuit (SMIC) on a single 10*10 mm LaAlO/sub 3/ substrate. Single-sided, coplanar line structures are used throughout the circuit with YBa/sub 2/Cu/sub 3/O/sub 7- delta / as conductor material. The oscillator was constructed around a GaAs MESFET as the active device. The complete oscillator is cooled by immersion in liquid nitrogen. An output power of 4.9 dBm was obtained. Single-sided noise power at 10 kHz offset from carrier was -90 dBc/Hz. >

Full-wave analysis of multilayer coplanar lines

A full-wave analysis of a coplanar waveguiding structure with multiple dielectric layers is presented. The results of a hybrid approach that combines the finite-element method and the conformal-mapping technique are compared with those of the spectral-domain approach. Numerical results for effective dielectric constants, characteristic impedances, current distributions, and field distributions for various multilayer coplanar line structures are presented and discussed. The computed results are compared with the available quasi-static ones. >

Hybrid quasistatic analysis for multilayer coplanar lines

A new quasistatic analysis of a coplanar waveguiding structure with multidielectric layers is presented, using a hybrid approach that combines the Galerkin finite-element method and the conformal-mapping technique. In the study, Wen&apos;s mapping function is adopted, which not only transforms the infinity problem domain into a finite region, but also overcomes the field singularity difficulty around the strip edges. Numerical results for effective dielectric constants, characteristic impedances, charge distributions and field distributions for various multilayer coplanar line structures are presented and the magnetic wall assumption over the slot is also investigated.