RF MEMS impedance tuners for 6–24 GHz applications

Abstract

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 (2 10 -2 13 ) 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.

RF-MEMS Based Tuner for Microwave and Millimeterwave Applications

“…Compared with MMIC-tuner, RF-MEMS architectures clearly exhibit improvement in term of achievable VSWR. In Ka-band, the losses of FET or Diode limit the VSWR of tuner to 20 (McIntosh et al, 1999;Bischof, 1994), whereas as for RF-MEMS-technology-based tuners exhibit values ranging from 32 (Kim et al, 2001) to even 199 (Vähä-Heikkilä et al, 2007). It clearly points out the breakthrough obtained by using RF-MEMS technologies for microwave and millimeterwave tuner applications.…”

“…It clearly points out the breakthrough obtained by using RF-MEMS technologies for microwave and millimeterwave tuner applications. Moreover, the demonstration of high RF-performances of RF-MEMS-based tuner have been successfully carried out: 1. on various architectures for o 1-stub (Vähä-Heikkilä et al, 2004-c;Dubuc et al, 2008;Bordas, 2008;Vähä-Heikkilä et al 2007), o 2-stubs (Papapolymerou et al, 2003;Kim et al, 2001;Vähä-Heikkilä et al, 2005;Vähä-Heikkilä et al, 2007) (Collin, 2001), the VSWR rises when the number of stubs increases. The table 4 presents the  MAX and VSWR values for 1, 2 and 3-stubs RF-MEMS tuners.…”

“…Table 5.  MAX and VSWR vs frequency for a 2-stubs tuner (Vähä-Heikkilä et al, 2007) A tradeoff between impedance coverage and high value of  MAX and VSWR then exists and both features need to be considered for fair comparison.…”

The Image Phase Approach for the Design of Rf Mems Shunt Switches

“…To this end the proper modeling of the membrane plays a crucial role. A number of papers have been published on this topic in literature [14][15][16][17][18][19]. Recently a general and accurate equivalent circuit has been developed in [8] for the coplanar bridge in the "up" position.…”

Broadband tunable matching networks utilizing tapered lines

“…The low-loss, high-linearity, miniature size and potential for low-cost have made research to explore a variety of designs. In particular, a number of high-performance matching networks have been already demonstrated based on several different topologies including single-, double-, triple-stub and double-slug tuners [1][2][3][4][5]. The basic approach in all these implementations is to utilize transmission lines loaded with either lumped (e.g.…”