UM9601_06 Datasheet, PDF (9/16 Pages) Microsemi Corporation – FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES

UM9601 – UM9608
FOR MICROSTRIP 900 MHz ANTENNNA SWITCHES
C OS O S
AND MICROWAVE APPLICATIONS
Microwave Characterization
The UM9601-UM9608 series has been designed and
characterized as shunt switch elements at frequencies to 4 GHz
in microstrip circuits. Performance curves are given which
demonstrate switch performance in 0.025” (.635mm) alumina
microstrip.
The performance data were derived by evaluating externally
biased microstrip circuits in which a UM9601 diode was
installed. Each circuit consisted of a 1 inch length of 50 Ohm
nominal impedance 0.025” (.635mm) thick alumina microstrip
and two SMA connectors. The data shown include the board
and connector loss. Measurements performed using 00.050”
(1.27mm) alumina substrates show similar performance at
frequencies to1.5 GHz
These circuits simulate SPST switches. Many designs
require multi-throw switches. It is important to recognize that a
multi-throw switch will have 6dB higher isolation than
indicated for SPST switches. Also, a multi-throw switch using
shunt mounted PIN diodes require the diodes be placed a
quarter-wavelength from the common port.
A further improvement in switch performance may be
achieved by using 2 shunt PIN diodes in each arm spaced a
quarter-wavelength from each other. In this case the isolation of
each section will be twice the dB value of the switch. The
insertion loss due to the diodes should be less than twice the
insertion loss of an SPST section due to the transforming effect
of the quarter-wave line on the capacitance of a single diode.
Copyright  2005
Rev. 0, 2006-01-17
Microsemi
Page 9