A band‐rejection type RF switch based on a dual‐mode microstrip ring resonator

Abstract

A band-rejection type RF switch, which has very high offstate isolation, low on-state insertion loss, and adjustable bandwidth, is proposed using a dual-mode ring resonator and two PIN diodes. To enable sharp band stop and dual-mode transmission, the ring resonator is directly fed using nonorthogonal feeding. Two PIN diodes are mounted in shunt after a quarter-wavelength transmission line from each feeding point, to turn the switch on and off and to reduce the size of the ring resonator. To estimate the practicable transmission characteristics of the proposed switch in relation to the angle of feeding and the wire-bonded PIN diodes, a lossy transmission-line equivalent circuit model is proposed, and even-odd mode analysis is carried out. The calculated frequency response shows good agreement with the measurement. The fabricated switch exhibits off-state isolation of 43.08 dB, and on-state insertion loss of 0.74 dB, within the range of 2.298-2.401 GHz.ABSTRACT: A band notched CPW UWB filter backed by rectangular rings is proposed. Initially, cascading of aperture-backed second-order microstrip filters is done to achieve the UWB passband. Later, to take advantage of the CPW geometry, the filter is converted to CPW configuration with rings at the back to achieve sharp cutoff characteristics and a notch at 5.1 GHz.

Fixed and Selectable Multiband Isolation of Double Pole Double Throw Switch Using Transmission Line Stub Resonators for Wimax and Lte

“…As a matter of fact, results of previous studies are also in a good isolation performance (> 25 dB). Yet, they are not appropriate to be utilized for high power applications due to their nature as (integrated circuits) [21], while the current research suits such application.…”

“…For switching elements in RF switch (including DPDT switch), researchers used either microelectro-mechanicals (MEMs) [10] or solid state elements such as PIN diode [19] and field effect transistor (FET) [13,14,20]. However, MEMs switches are not suitable for high power applications due to their limited power capabilities [21]. Moreover, they have not found wide use in RF and microwave applications since the PIN diode was developed and commercialized [22].…”

“…Discrete PIN diodes were used in the proposed DPDT switch due to its advantage of higher power levels used in wireless communication systems. Generally, resonators were used to build up several RF and microwave circuit designs such as antennas [20], amplifier [21], filter [22] and microwave absorber [24]. Thus, by using this technique (resonator) and together with discrete PIN diodes in DPDT switch design, the key advantage is a multiband high isolation with minimum number of PIN diodes as compared to conventional multiple cascaded PIN diodes.…”

Selectable multiband isolation of single pole double throw switch using transmission line stub resonator for WiMAX and LTE applications

“…RF switch (such as SPDT switch) elements can be categorised as micro-electro-mechanicals (MEMs) [22] or solid state elements such as PIN diode [9,11] and field effect transistor [10,23]. However, MEMs switches are not suitable for high-power applications due to their limited power capabilities [24]. Moreover, they have not been widely used in RF and microwave applications since the PIN diode was developed and commercialised [20].…”

“…Discrete PIN diodes were used in the proposed SPDT switch due to its advantage of higher power levels used in wireless communication systems. Generally, resonators were used to build up several RF and microwave circuit designs such as antennas [20], amplifier [21], filter [22], switch [29] and microwave absorber [24]. Thus, by using this technique (resonator) and together with discrete PIN diodes in SPDT switch design, the key advantage is a multiband high isolation with minimum number of PIN diodes when compared with conventional multiple cascaded PIN diodes.…”