I understand what you are looking for and I don't think you will be able to find such a fund. The reason is that publicly traded investment funds will invest only in investment vehicles that are generally regulated or in which there can be some transparency of the investment (at least to the managers of the fund) because they are under scrutiny by the regulators.
Unlike in investments such as Mortgage-Backed Securities or other "financial derivatives", there are no easily "saleable" metrics that a packager of an "intellectual property portfolio" can create or obtain (eg: we are going to use $50 Million dollars to buy 50 patents and sue the pants off of everyone with an expected return of $100 Million). Finding a handful of private Qualified Investors is easier and more cost-effective for those raising capital to fund such a portfolio than being able to create a salable "public offering" for such capital raising efforts.
It would be very risky for a publicly-traded fund to actively create a fund for the exclusive purchase of such derivative and other investments that no fund would dare take that risk for potentially unsophisticated customers.
If you want to invest in a portfolio of litigation ventures, IP, and other similar types of high-risk investments, you would likely have to join some sort of private pooled effort that is not subject to regulatory scrutiny.