While the glamour in wireless and RF applications may be in the complex circuitry, the antenna and associated components are equally important. The UPD5710TK CMOS SPDT switch IC from NEC supports transmit/receive (T/R) switching, diversity antennas, and band select functions, at a lower cost than GaAs devices and lower parts count than PIN diodes, but with comparable specifications. The dc to 2.5GHz device has insertion loss of 0.6dB to 1GHz, and 0.8dB at 2.0GHz, while isolation is 32.5dB and 25dB, respectively, at those frequencies.
You control the function with a single low-voltage signal, and the switch doesn't require blocking capacitors on the RF lines, so you can use it down to dc. Housed in a 1.131.530.55mm flat-lead, lead-free package, the switch is 19 cents in 100k lots.
Bill Schweber
NECFax 81-3-3457-7249
www.nec.com
