CoMpaReD To monolithic-microwaveintegrated- circuit (MMiC) devices in QfN packages, the MsW2000 series of surfacemount, piN-diode single-pole, double-throw (sp2T) switches claim to provide superior low- and high-signal performance. The 8-x- 5-x-2.5-mm sp2T switches are designed in both asymmetrical and symmetrical topologies. The asymmetrical sp2T design comprises a unique geometry transmit (Tx) series piN diode that provides series resistance (Rs) below 0.7 O at 100 ma for improved power dissipation and higher input third-order intercept values. The thermal resistance of the Tx piN diode is on the order of 6C/W, allowing it to safely handle CW incident power levels exceeding 100 W at +85C. The receive (Rx) port incorporates a series piN diode in addition to a shunt piN diode floated on a Rf bypass capacitor, allowing for positive voltage-only operation. This arrangement provides improved Tx-Rx isolation in excess of 40 dB. alternatively, it allows less than +10 dBm leakage to the receiver port with a +50-dBm Tx signal applied. The switches can operate in either a high-signal 100-W CW cold-switched mode or in a hot-switched condition, in which the Rf power-state-change commutation period from transmit port to antenna to antenna to receive port is less than 100 ns. The sp2T family handles 500 W peak power at a 50-s Rf pulse width at 5 percent duty cycle at +85C. These switches are optimized in design to function in two frequency bands of interest: 10 to 1000 MHz and 400 to 4000 MHz. in band 1, for example, the asymmetrical sp2T switch typically exhibits transmit-port-to-antenna insertion loss of 0.2 dB with better than 20-dB return loss and 45-dB transmit-receive isolation. The antenna-to-receive-port loss is similar at 0.3 dB with greater than 20-dB return loss and better than 20-dB receive-port-to-transmit-port isolation.
Aeroflex/Metelics, 54 Grenier Field Rd., Londonderry, NH 03053; (888) 641-7364, FAX: (603) 641-3500, Internet: www.aeroflex.com.
