Millimeter-wave antennas have been developed for various applications such as broadband high-speed wireless communication systems and automotive radar systems. Microstrip antennas are more advantageous than other millimeter-wave antennas at the viewpoints of low profile and low cost [1]. On the other hand, transmission loss of microstrip line is significant problem in array feeding. So, microst...

In this paper, several geometries of a class of grounded coplanar waveguide (GCPW) are investigated using the finite difference time domain (FDTD) method, and their losses are computed. A uniform grounded coplanar waveguide (GCPW) structure is used as a reference case for the other non-uniform geometries. First, four geometries are proposed to study the transmission and loss effect of replacing...

Abstract—A microstrip 180◦ phase shifter obtained by a novel design of Microstrip-to-Coplanar Waveguide (CPW)-to-Microstrip transition is presented. The proposed phase shifter is obtained without changing the layer of the second microstrip line. Via holes are used to transfer the current from the top to the bottom substrate layer and vice versa. The presented phase shifter is operating in a wid...

Differential evolution (DE) algorithm is applied to the design of single-layer and multi-layer microstrip antennas. For the design of single-layer co-axial probe-fed microstrip antenna, fitness function is obtained from cavity model theory of microstrip antenna, whereas for the design of multi-layer aperture-coupled microstrip antenna, transmission line model is used to obtain fitness function ...

Nowadays, more and more technologies are implemented in vehicles to improve driver assistance in order to enlarge comfort and avoid accidents. Automotive radar systems have been gradually installed into vehicles with the growth of wireless technologies. Among the utilizations of automotive radar systems, survey around automobiles for the prevention of traffic accidents is one of the prospective...

The frequency-dependent characteristics of microstrip planar circuits have been previously analyzed using several full-wave approaches. All those methods directly give characteristic of the circuits frequency by frequency. Computation time becomes important if these planar circuits have to be studied over a very large bandwidth. The transmission line matrix (TLM) method presented in this paper ...

This paper mainly presents a briefly review for recent progress in MEMS-based transmission lines for use in microwave and millimeterwave range. MEMS-based transmission lines including different transmission line structure such as membranesupported microstrip line microstrip line, coplanar microshield transmission line, LIGA micromachined planar transmission line, micromachined waveguides and co...

We have developed a broad-band technique for measuring the relative permittivity of lowthin films using microstrip transmission-line measurements. From measurements of the complex microstrip propagation constant and the characteristic impedance, we determined the relative permittivity of thin films incorporated in microstrip lines. We present measurement results to 40 GHz for both an oxide and ...