What is IIP3?

The terms IIP3 and OIP3 stands for Input Third Order Intercept Point and Output Third Order Intercept Point respectively. Introduction: When two or more than two signals are mixed in nonlinear component whether active or passive, other signals get generated as a result of product of these original signals.

What is IIP3 in LNA?

A low-noise amplifier (LNA) that achieves high third-order input intercept point (IIP3) at RF frequencies using a nonlinearity cancellation technique is proposed. The circuit tackles the problem of the effect of the second-order nonlinearity on IIP3 at RF frequencies.

How is OIP3 calculated?

In Figure 10, POUT and ΔP are measured directly on the screen; further, OIP3 = POUT + ΔP/2.

What causes intermodulation distortion?

Intermodulation (IM) or intermodulation distortion (IMD) is the amplitude modulation of signals containing two or more different frequencies, caused by nonlinearities or time variance in a system. IMD is only distinct from harmonic distortion in that the stimulus signal is different.

How do you calculate intermodulation product?

The order of the intermodulation product depends on how many input signals are mixed and which harmonics of each of those input signals have mixed. Second-order and third-order intermodulation products are defined as follows. 2 f 1 + f 2 = f 6 f 1 + 2 f 2 = f 7 2 f 1 − f 2 = f 8 2 f 2 − f 1 = f 9 .

How do you get rid of intermodulation distortion?

Make sure to use top-notch gear and high quality, low loss coax. Avoid active antennas. Counterintuitively, active antennas that boost gain can sometimes introduce unwanted intermodulation signals and cause distortion. Likewise, being too closeto a transmitter or using an amplified transmitter can produce IMD as well.

How can intermodulation distortion be prevented?

How to prevent Intermodulation

  1. Use high quality components and avoid non-linear active components in design of devices.
  2. Operate power amplifiers in linear range to avoid intermodulation components.
  3. Avoid low quality mechanical switches and poor contact signal adaptors.

When does a cascaded 2 Tone IP3 occur?

Cascaded 2-Tone, 3rd-Order Intercept Point (IP3) If the device was not limited in output power, then the powers of the intermodulation products would increase in power until they were eventually equal in power with the input tones at the output.

How to calculate the IP3 of a cascaded budget?

Cascading IP3 Values in a Chain of Components. Calculating the cascaded values for 3rd-order intercept point (IP3) for the system budget requires use of ratios for gain and power levels for IP3 (do not use dB and dBm values, respectively). The standard format for indicating decibel values is to use upper case letters; i.e., IP3 for units of dBm.

Which is an example of a cascaded system?

Click here to view an example of a cascaded system. Assuming a gain of 1 (0 dB) the slope of the fundamental gain line would be 1:1; the slope of the 3rd-order gain line would be 3:1.

Is the organized Cascade intercept method too conservative?

The organized cascade intercept method often provides an overly conservative (i.e., far too low) estimate of OIP3T and IIP3T distortion. If the phases of the stages are random (or perhaps unknown), then it is reasonable to add the powers of the distortion terms.