Modifying the MAX2010 for Operation at 360MHz

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Abstract

This application note showcases simple changes to a standard EV kit for the MAX2010 (adjustable RF predistorter) to optimize its operational frequency to 360MHz. By default, this predistortion component is specified for 500MHz to 1100MHz operation. However, a few modifications to a standard MAX2010 EV kit can optimize its operation for lower frequency operation.

Overview of Modifications

Experimentation has shown that the frequency range of the MAX2010 adjustable RF predistorter can be extended below 500MHz by implementing simple changes to the input and output matches of the phase section. Note that these changes pertain to the phase section only. Similar changes may be possible for the gain section as well, though Class AB applications are best served by employing only the phase expansion from the MAX2010.

Using the standard MAX2010 EV kit (Figure 1), modify the following components to yield optimal performance at 360MHz:

C1: change from 100pF to 330pF

C11: change from 2.2pF to 5.6pF

L1, L2: change from 5.6nH to 19nH (Coilcraft 0402CS-19NXJB)

C12: change from 2.2pF to 5.6pF

C10: change from 100pF to 220pF

Figure 1. MAX2010 EV kit schematic.

Figure 1. MAX2010 EV kit schematic.

Resulting Phase-Expansion Characteristics at 360MHz

The plot in Figure 2 depicts the typical phase expansion possible at 360MHz after employing the changes outlined in the previous section.

Figure 2. MAX2010 phase-expansion characteristics at 360MHz.

Figure 2. MAX2010 phase-expansion characteristics at 360MHz.

Input-Matching Characteristics at 360MHz

Figure 3. MAX2010 input match at 360MHz.

Figure 3. MAX2010 input match at 360MHz.

Output-Matching Characteristics at 360MHz

Figure 4. MAX2010 output match at 360MHz.

Figure 4. MAX2010 output match at 360MHz.