Quadrature Modulator
CMX993/CMX993W
10. Typical output power is achieved with the typical input drive level stated on I and Q channels,
operation at 500MHz (sine and cosine waveforms on I and Q respectively).
11. Two tone test, limit met at all gain steps for ‘Forward Path Output Power Level (PEP)’ of:
maximum output power below 600MHz, typical output power 600-900MHz, and 0dBm above
900MHz.
12. Measured with modulated output signal at relevant output power for forward path attenuations
as specified.
13. Operating into a virtual earth (not ground).
14. Normally connected to BVREF pin via RC filter, the tolerance of BVREF is specified in the DC
Parameter table and these same tolerance limits apply here.
15. With a load of 1k in parallel with 100pF. (Note 17 also applies).
16. Includes all IMD products up to and including the 7th order products e.g. 2nd, 3rd, 5th etc.
Specification limit applies to each IMD product, not composite power of all products.
17. For small signal operation. It is recommended that for this application the input levels be
restricted to +/-0.4V about a defined reference voltage of 1.6V (nominal); this will allow for
some tolerance in components and for the precision of the reference voltage setting.
18. The inputs are protected with diodes. These diodes prevent the inadvertent application of
voltages that may cause damage to the input transistors.
19. Two-tone test with value measured relative to power in either tone, unity gain, 0.8V p-p signal
with two tones at 70kHz and 90kHz (400mV p-p each tone).
20. The output power appropriate for a particular application depends on the type of modulation
and the spectral purity requirements in each particular case. For some applications it may be
necessary to operate the output level below the specified typical level in order to achieve the
desired results. Note also that the intermodulation performance, which influences the
achievable output level, varies with frequency, see Note 11.
21. This is the impedance that should be presented to the output of the up-converter, e.g. using a
balun. The precise load impedance may be optimised for a given operating frequency, or band
of frequencies, to achieve improved output level and signal-to-noise ratio.
22. With a spurious-free LO input and specified output level.
23. Measured with MODIN, MODIP, MODQN, MODQP connected to BVREF with 10 resistors
decoupled by 33nF capacitors.
24. Voltage gain measured from modulator input (MODIN or MODQN) to output of a 4:1 balun,
using 7kHz sine/cosine waves on MODIN/MODQN.
25. Measured at 20MHz offset from the operating frequency, all modulator I/Q inputs at BVREF
.
26. Performance measured based on IS-95B section 6.1.4.1.1; measurement bandwidths 1.23MHz
for wanted and 3rd adjacent channel and 30kHz for 1st and 2nd adjacent channels.
27. LO divide by 2 mode operation only.
28. LO divide by 4 mode is not recommended for output frequencies below 50MHz.
29. Specification applies over the range 100MHz to 1GHz.
30. A typical figure at 40MHz or 50 MHz is –146dBc/Hz at a 5MHz offset.
31. The maximum value is derived from analysis of statistical evaluation results and is not
guaranteed by 100% testing.
32. Gain and Output Power will reduce below 100MHz. Values are typically 4dB lower at 30MHz.
33. For operation with a modulator output above 600MHz optimum performance will typically be
achieved with the LO input level in the range -15dBm to -20dBm.
2013 CML Microsystems Plc
24
D/993/10
CMLMICRO [ CML MICROCIRCUITS ]
