Philips Avalon CTS M2720A, Service Manual

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Antenna System Guidelines 1 General Information
15
Specifications
Antenna system calculations for fetal telemetry differ from those of adult M1402A or M2602A mainframe
systems. The M2720A uses an internal signal amplifier, requiring the antenna system to have a 0db to
-3db gain at the final antenna connection to the Avalon CTS.
The minimum carrier to noise ratio (CNR) should be 8dB.
M2720A Avalon CTS typical specifications:
Mixed Telemetry Devices on the Same M2600A Antenna System
A mixture of M2720A and other supported Philips telemetry devices (for example, M1310A or M2600A
Adult Telemetry Transmitter/Receiver) on the same antenna system are supported under the following
conditions:
• M2600A antenna system design rules are followed.
• Antenna input must be within the range of 0dB to -3dB.
• Each Avalon CTS channel must be separated by a minimum of 100 KHz from any non-Avalon
frequency channel.
• The internal channel frequency spacing between Avalon CTS transducers should be 25 KHz (factory
default setting).
Example:
A Series 50 T Fetal Telemetry System (M1310A) is already connected to an antenna system, and its
transmitter is set to 433.650 MHz. You need to connect an Avalon CTS to the same antenna system. In
this case, the first usable frequency channel for any M2720A transducer is either 433.550 MHz or 433.750
MHz, as each transducer frequency channel must be separated by at least 100 KHz from any frequency
channel used by any telemetry device other than Avalon CTS transducers.
M2720A
Frequency Band
Maximum
Input Before
Saturation
Carrier to
Noise
Ratio
(CNR)
Gain
Noise
Figure
(NF)
Third Order
Intercept
point (TOI)
@100KHz
Input 1dB
compression
point
(P 1 dB)
ISM
(433-443 MHz)
0 to -3db 8 dB 14.1 dB* 7.36* 5 dBm* -4 dBm*
Japan
(420-430 MHz)
0 to -3db 8 dB 14.6 dB* 6.86* 5 dBm* -4 dBm*
WMTS
(608-614 MHz)
0 to -3db 8 dB 11.1 dB* 8.55* 5 dBm* -4 dBm*
*
Can be added to the antenna design spreadsheet as M2720A-specific parameters