Transmitter

Item

Values

TX frequency range

890 ... 915 MHz

Type

Up conversion

Intermediate frequency

116 MHz

Maximum output power

0.8 W (29 dBm)

Power control range

16 dB

Maximum RMS phase error

5 deg.

Maximum peak phase error

20 deg.

Technical Documentation System Module

Modulator circuit, TX part of the CRFRT

The modulator of the CRFRT is a quadrature modulator. The input local signal (232 MHz) is divided by two to get accurate 90 degrees phase shifted signals for the I/Q mixer. After mixing the signals are combined and amplified. The output of the IC is single ended and the level is controllable. The maximum output level is 0 dBm, typically. (part code 4370091.)

Parameter

Minimum

Typical / Nominal

Maximum

Unit / Notes

Supply voltage

4.27

4.73

V

Supply current

35

mA, norm. operation

Transmit Frequency Input

Minimum

Typical / Nominal

Maximum

Unit / Notes

LO input frequency

170

400

MHz

LO input power level

-20

-10

0

dBm

LO input impedance

70

100

130

ohm

Modulator Inputs (I/Q)

Minimum

Typical / Nominal

Maximum

Unit / Notes

Input bias current

100

nA

External DC reference

2.1

2.6

V

Differential input swing

0.5

0.8

1.1

Vpp

Differential input offset voltage

0

1.0

3.0

mV

Input impedance

200

kohms

Gain unbalance

-0.5

0.5

dB

Modulator Output

Minimum

Typical / Nominal

Maximum

Unit / Notes

Available RF power

-45.0

0.0

dBm, ZiL= 50 ohms

Suppression of 3rd order prods

-35

dB, Pout = -13 dBm

Carrier suppression

35

dB

Noise floor at saturated Pout

-125

dBm/Hz

Was this article helpful?

0 0

Post a comment