CPW-fed slot antennas on multilayer dielectric substrates

Coplanar wave (CPW)-fed slot antennas printed on multilayer dielectric substrates are numerically analyzed using a full-wave integral equation technique and the method of moments. The Green's function is derived with an iterative formulation. Results obtained with a simplified and a rigorous model of the feeding CPW lines are compared. The mutual coupling between the slot antennas in an array environment is calculated for a three-layer high-low-high permittivity combination. The theoretical results are verified with measurements     

RF MEMS impedance tuners for 6–24 GHz applications

RF MEMS tuners with wide impedance coverage have been developed for 6–24 GHz noise parameter and load‐pull measurement systems. The tuners are based on triple‐, double‐, and single‐stub topologies loaded with switched MEMS capacitors. Several designs are presented, and they use 10–13 switched MEMS capacitors to produce 1024–8192 (2¹⁰–2¹³) different impedances. The measured impedance coverage agrees well with simulations and it is the widest ever measured impedance coverage from any planar tuner to‐date. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.     

A 94-GHz aperture-coupled micromachined microstrip antenna

This paper presents an aperture-coupled micromachined microstrip antenna operating at 94 GHz. The design consists of two stacked silicon substrates: (1) the top substrate, which carries the microstrip antenna, is micromachined to improve the radiation performance of the antenna and (2) the bottom substrate, which carries the microstrip feed line and the coupling slot. The measured return loss is -18 dB at 94 GHz for a 10-dB bandwidth of 10%. A maximum efficiency of 58±5% has been measured and the radiation patterns show a measured front-to-back ratio of -10 dB at 94 GHz. The measured mutual coupling is below -20 dB in both E- and H-plane directions due to the integration of small 50-μm silicon beams between the antennas. The micromachined microstrip antenna is an efficient solution to the vertical integration of antenna arrays at millimeter-wave frequencies