Ceyhun Karpuz

Characteristics of periodically loaded CPW structures

A capacitively loaded coplanar waveguide (CPW) resonator has been studied. It has been shown that the proposed resonator can be used to achieve a slow-wave effect without occupying extra surface area and it has a good performance as compared with the conventional half-wavelength CPW resonator. Furthermore, dispersive effects have been increased with the number of slots in periodically loaded structures.

Miniature Dual-Mode Microstrip Filters

In order to reduce the size of dual-mode microstrip filters by keeping excellent performance, novel filter geometry is proposed. The novel filter includes a dual-mode resonator based on a meander structure. The effect of input/output feed lines located along a straight line on filter response is investigated for the dual-mode filter. The coupling between degenerate modes of the proposed dual-mode microstrip resonator is discussed depending on the perturbation size. The two dual-mode microstrip bandpass filters with real axis and imaginary axis transmission zeros (TZs) are designed, fabricated, and measured to document the validity of the description of the positive and negative coupling coefficient

A reduced-size dual-mode bandpass filter with capacitively loaded open-loop arms

A novel type of dual-mode microstrip bandpass filter using degenerate modes of a dual-mode microstrip square loop resonator with capacitively loaded open-loop arms is proposed. Such a dual-mode bandpass filter with a 0.75% bandwidth at the center frequency of 1.603 GHz is designed and fabricated to demonstrate the design of reduced-size microstrip filters. It is shown that the proposed filter has a size reduction of about 59% at the same center frequency, as compared with the dual-mode bandpass filters such as microstrip patch, cross-slotted patch, square loop and ring resonator filter.

Asymmetric Dual-Mode Microstrip Filters with Adjustable Transmission Zero

A new type of dual-mode resonator that produces asymmetrical frequency responses is proposed. The effect of nonorthogonal input/output feed lines located along a straight line on filter response is investigated for the dual-mode filter. The coupling between degenerate modes of the proposed dual- mode microstrip resonator is discussed depending on the perturbation size. The two samples of asymmetric dual-mode microstrip filter were designed, fabricated and measured to demonstrate the design of dual-mode microstrip filters exhibiting transmission zero shifting property. The one of them produces a filter characteristic with two TZs in the upper stopband the other has two TZs in the lower and upper stopbands. The shifting of the one of the TZs from one side of the passband to the other is realized by only changing the perturbation size.

Quasistatic analysis of cylindrical coplanar strip lines

CAD-oriented analytic formulas are given for calculating the quasistatic parameters of the cylindrical coplanar strip (CCPS) lines. The curvature effects on the quasistatic characteristics of CCPS are investigated by using conformal mapping techniques. The calculated results are compared with those obtained for a corresponding planar CPS and asymmetrical CPS.xa0© 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 17: 148–151, 1998.

Analytic formulas for conductor-backed asymmetric CPW with one lateral ground plane

Closed-form analytical expressions suitable for CAD software packages are presented for calculating the quasistatic TEM parameters of a conductor-backed asymmetric coplanar waveguide (CB ACPW) with one lateral ground plane. The effect of the removal of one of the lateral ground planes of the conventional ACPW and additional backed ground plane on the quasistatic parameters is discussed by using the expressions derived by the conformal mapping techniques. This papers results are compared with the results available in the literature.xa0©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 22: 123–126, 1999.

Effect of upper shielding and conductor backing on quasistatic parameters of asymmetric coplanar waveguides

CAD-oriented analytic formulas are presented for calculating the quasistatic parameters of the conductor-backed asymmetric coplanar waveguide (ACPW), the ACPW with upper shielding, and the conductor-backed ACPW with upper shielding using conformal mapping techniques. The effect of the presence of the upper shielding and the conductor-backing on the quasistatic TEM parameters is discussed. It is also presented that the expressions derived in this work can be used for calculating the quasistatic parameters of various symmetric and asymmetric CPWs.xa0©1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 394–402, 1999

Quasistatic analysis of cylindrical coplanar waveguide with multilayer dielectrics

CAD-oriented analytic formulas are given for calculating the quasistatic parameters of the cylindrical CPW with three dielectrics. The effects of the dielectric materials on the quasistatic characteristics are investigated by using conformal mapping techniques. The calculated results are compared with those obtained for a corresponding planar CPW and a cylindrical CPW with a single dielectric. The curvature effects on the quasistatic characteristics are discussed. Moreover, the present expressions can also be extended to the cylindrical CPW with multilayer dielectrics.xa0© 1998 John Wiley & Sons, Inc. Int J RF and Microwave CAE 8: 303–314, 1998.

Cross-Coupled Bandpass Filter using Microstrip Triangular Open-Loop Resonators

A new cross-coupled planar microwave filter is proposed using coupled microstrip triangular open-loop resonators. The full-wave EM simulator is used to design the triangular resonator and to calculate the coupling coefficients of three basic coupling structures encountered in this type of filter. A four-pole elliptic function filter of this type is designed and fabricated. Measured filter performance is compared with the simulated performance.

Quasi-TEM analysis of broadside-coupled V-shaped microshield coplanar waveguides

A new type of broadside-coupled CPWs (BC CPWs) is proposed using a V-shaped microshield CPW. Closed-form expressions are presented for calculating the quasistatic parameters of this coupled structure by using conformal mapping techniques. The effect of the V-shaped conductor backing on the quasistatic parameters and the coupling between CPWs are also discussed. Comparisons are made between the present numerical results and the results available in the literature for general BC CPWs. The coupling coefficient of the present BC CPWs is shown to be significantly lower than that of general BC CPWs.xa0© 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 26: 229–232, 2000.