Hi, you are going to struggle to get much better than 100db dynamic range, especially in a portable device. I have several VNA’s including fieldfox, anritsu, HP, Agilent, Measall KC901 and others. The Measall does just give approximately 100db range, but a lot of the Chinese cheaper units won’t meet their specs. My best unit for the frequency range that you are looking at is the HP 4396a which gives me a min of 130db dynamic range. As others have suggested, a good spec analyser with a tracking generator will give at least 110db, usually 120db or more. The HP 8920 radio test set with its spec an and tracking gen will give 110+ db dynamic range, and you can use a return loss bridge with it for S11 measurements. Beyond the 100db point in VNA’s, things get very difficult in engineering to maintain isolation and keep internal losses down from bridges, impedance matching etc as well as getting detectors sensitive enough for phase measurements. For tuning tight notches, we often just use a spec analyser with tracking, as it has a slightly better dynamic range than using the equivalent VNA.