MAX2010ETI-T

Maxim > Design Support > Technical Documents > Application Notes > Communications Circuits > APP 3955 Keywords: frequency range, class AB applications, phase expansion, parasitic gain compression, input matching, output matching, RF predistortion APPLICATION NOTE 3955 Modifying the MAX2010 for Operation at 450MHz Dec 08, 2006 Abstract: This application note showcases simple changes to a standard EV kit for the MAX2010 (adjustable RF predistorter) to optimize its operational frequency to 450MHz. 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 also be possible for the gain section, 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 450MHz: C11: change from "not installed" to 4.7pF C1: change from 8.2pF to 330pF L1: change from 5.6nF to 15nH C12: change from "not installed" to 4.7pF L2: change from 5.6nF to 15nH Page 1 of 5 Figure 1. MAX2010 EV kit schematic. Resulting Phase-Expansion Characteristics at 450MHz The plot in Figure 2 depicts the typical phase expansion possible at 450MHz after employing the changes outlined in the previous section. Page 2 of 5 Figure 2. MAX2010 phase expansion characteristics at 450MHz. Parasitic Gain-Compression Characteristics at 450MHz The graph in Figure 3 displays the typical gain-compression characteristic that can be achieved after changing the aforementioned components to their new values. Page 3 of 5 Figure 3. MAX2010 parasitic gain-compression characteristics at 450MHz. Input-Matching Characteristics at 450MHz Page 4 of 5 Figure 4. MAX2010 input match at 450MHz. Output-Matching Characteristics at 450MHz Figure 5. MAX2010 output match at 450MHz. Related Parts MAX2010 500MHz to 1100MHz Adjustable RF Predistorter Free Samples   More Information For Technical Support: http://www.maximintegrated.com/support For Samples: http://www.maximintegrated.com/samples Other Questions and Comments: http://www.maximintegrated.com/contact Application Note 3955: http://www.maximintegrated.com/an3955 APPLICATION NOTE 3955, AN3955, AN 3955, APP3955, Appnote3955, Appnote 3955 Copyright © by Maxim Integrated Products Additional Legal Notices: http://www.maximintegrated.com/legal Page 5 of 5