TXM-900-HP-II Linx Technologies Inc, TXM-900-HP-II Datasheet - Page 7

• Manufacturer Part Number: TXM-900-HP-II
• Description: TRANSMITTER RF 900MHZ 8-CHANNEL
• Manufacturer: Linx Technologies Inc
• Series: HP2r

Specifications of TXM-900-HP-II

• Frequency: 902MHz ~ 928MHz
• Applications: ISM, RKE, Security and Fire Alarms
• Modulation Or Protocol: FM, FSK
• Data Rate - Maximum: 50 kbps
• Power - Output: -3dBm ~ 4dBm
• Data Interface: PCB, Through Hole
• Antenna Connector: Through Hole
• Voltage - Supply: 2.17 V ~ 16 V
• Operating Temperature: 0°C ~ 70°C
• Package / Case: SIP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Features: -
• Memory Size: -
• Current - Transmitting: -
• Other names: TXM-900-HP2; TXM-900-HP2

MICROSTRIP DETAILS
Figure 14: Microstrip formulas (Er = Dielectric constant of pc board material)
mount type. They should be grouped closely and the overall trace to the antenna
kept as short as possible. Calculate the feed-trace width as shown under the
“Microstrip Details” section of this manual and the trace should pass over a
suitable ground-plane. Further details regarding T-pad values can be found in
application note #00150 - “Use and Design of T-Attenuation Pads”.
A transmission line is a medium whereby RF energy is transferred from one
place to another with minimal loss. This is a critical factor, particularly in high-
frequency products like the HP-II because the trace leading to the module’s
antenna can effectively contribute to the length of the antenna, changing its
resonant bandwidth. In order to minimize loss and detuning, some form of
transmission line between the antenna and the module is needed, unless the
antenna connection can be made in close proximity:<1/8 in. to the module. One
common form of transmission line is coax cable, another is the microstrip. The
term refers to a PCB trace running over a ground-plane which is designed to
serve as a transmission line between the module and the antenna.The width is
based on the desired characteristic impedance, the thickness of the PCB, and its
dielectric constant. The correct trace width can be easily calculated using the
information below.
Dielectric
Constant
2.55
4.8
4
Width/Height
(W/d)
1.8
2
3
Dielectric Characteristic
Constant
Effective
3.59
3.07
2.12
Impedance
48.0
50.0
51.0
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