Even without "High-End" power DAC (D class power amplifier) required dynamic range of the measurement devices can be estimated: e.g., Texas Instrument TAS5518-5261K2EVM  intermodulation distortion
decline for 5th harmonics even -90 dB for output level of 300 / 500 mW (Fig.
One possible way to achieve this design goal is to rely on certain bias points and power operating conditions, the so-called large-signal intermodulation distortion
(IMD) sweet spots, which lead to improved carrier-to-IMD ratios (IMR) near the zones where power-added efficiency (PAE) is maximized.
When signals are amplified in an HPA, unwanted harmonics and intermodulation distortion
signals are generated, in addition to the amplified desired signals, by the nonlinear characteristics of the power amplifier.
(1.) Notes on Intermodulation Distortion
It extracts the low second-order frequency intermodulation distortion
signal from the input signals and uses it as the mixing signal source.
The company asserts the ADC's dynamic performance of -147 dBm/Hz noise floor, 52 dB noise power ratio (NPR) and -61 dBFS intermodulation distortion
(IMD) enables a new generation of software-defined radio (SDR) architectures and applications.
Examples of other tests that require a spectrum analyzer or vector signal analyzer include testing for intermodulation distortion
, third-order intercept, the 1-dB gain compression on a power amplifier or power transistor, and a device's frequency response.
The procedure of generating the third-order intermodulation distortion
required for the linearization of the laser diode (type Ortel model 3540A-022 fiber optic transmitter) uses the diode equivalent circuit.
RF power amplifier (RFPA) nonlinearities introduce third-order intermodulation distortion
(IMD) to the amplifier output signal when driven by a multitone input signal.
In addition, since power levels are low, intermodulation distortion
is not a consideration.