CCT-48K/CT-48K Page 10

SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE

© 2019 TELEDYNE COAX SWITCHES

CCT-48K\CT-48K\042019\Q2

Series CCT-48K/CT-48K

Internal 50Ω Termination DC-40 GHz

Normally Open Multi-Throw Coaxial Switch

Actuator

An actuator is the electromechanical mechanism that transfers the

RF contacts from one position to another upon DC command.

Arc Suppression Diode

A diode is connected in parallel with the coil. This diode limits the

“reverse EMF spike” generated when the coil de-energizes to 0.7

volts. The diode cathode is connected to the positive side of the

coil and the anode is connected to the negative side.

Date Code

All switches are marked with either a unique serial number or a

date code. Date codes are in accordance with MIL-STD-1285

Paragraph 5.2.5 and consist of four digits. The first two digits

define the year and the last two digits define the week of the year

(YYWW). Thus, 1032 identifies switches that passed through final

inspection during the 32nd week of 2010.

Indicator

Indicators tell the system which position the switch is in. Other

names for indicators are telemetry contacts or tellback circuit.

Indicators are usually a set of internally mounted DC contacts

linked to the actuator. They can be wired to digital input lines,

status lights, or interlocks. Unless otherwise specified, the

maximum indicator contact rating is 30 Vdc, 50 mA, or 1.5 Watts

into a resistive load.

Isolation

Isolation is the measure of the power level at the output connector

of an unconnected RF channel as referenced to the power at the

input connector. It is specified in dB below the input power level.

Multi-Throw Latching Switch

A multi-throw switch is a switch with one input and three or more

output ports. The CCT-48K can switch a microwave signal to any

of 2,3,4,5 or 6 output from a single common input.

Switching Time

Switching time is the total interval beginning with the arrival of the

leading edge of the command pulse at the switch DC input and

ending with the completion of the switch transfer, including contact

bounce. It consists of three parts: (1) inductive delay in the coil, (2)

transfer time of the physical movement of the contacts, and (3) the

bounce time of the RF contacts.

TTL Switch Driver Option

As a special option, switch drivers can be provided for both failsafe

and latching switches, which are compatible with industry-standard

low-power Schottky TTL circuits.

TD-Option

This option includes a decoder. The 3-bit parallel command is

decoded to internally select the appropriate position. See the logic

tables. The TD-Option increases the Vsw supply current demand

by 50mA max at 28Vdc and +20°C.

Performance Parameters vs Frequency

Generally speaking, the RF performance of coaxial switches is

frequency dependent. With increasing frequency, VSWR and

insertion loss increase while isolation decreases. All data sheets

specify these three parameters as “worst case” at the highest

operating frequency. If the switch is to be used over a narrow

frequency band, better performance can be achieved.

Actuator Current vs Temperature

The resistance of the actuator coil varies as a function of

temperature. There is an inverse relationship between the

operating temperature of the switch and the actuator drive current.

For switches operating at 28 VDC, the approximate actuator drive

current at temperature, T, can be calculated using the equation:

Magnetic Sensitivity

An electro-mechanical switch can be sensitive to ferrous materials

and external magnetic fields. Neighboring ferrous materials should

be permitted no closer than 0.5 inches and adjacent external

magnetic fields should be limited to a flux density of less than 5

Gauss.

GLOSSARY