In addition to the other alternatives described by WA4SCA, Let me also suggest another nice VNA (Vector Network Analyzer) -- the Mini-VNA and Mini-VNA PRO made in Europe and available in the US from http://www.w4rt.com/ and Gigaparts (http://www.gigaparts.com/gpsales/1002/store.php?action=profile&sku=ZW4-M... http://www.gigaparts.com/gpsales/1002/store.php?action=profile&sku=ZW4-MINIVNA and http://www.gigaparts.com/gpsales/1002/store.php?action=profile&sku=ZW4-M... http://www.gigaparts.com/gpsales/1002/store.php?action=profile&sku=ZW4-MINIVNA-PRO).
I got my Mini-VNA PRO last year at Dayton from W4RT and I find it to be a most interesting widget. It is a full 2-port VNA covering the entire 0.1-200 MHz range. It is intended to be used with a Windoze computer (my Lenovo Netbook is more than adequate) and normally connects via USB. The USB port provides DC power, either to run the unit or to charge its internal LiPO battery.
It is battery powered and can also interface via a wireless Bluetooth serial port. One nifty thing here -- you can put the entire VNA at the feedpoint of an antenna (very useful with an HF wire), hoist it into the air and measure the intrinsic feedpoint impedance with NO cables attached, making all measurements using the wireless Bluetooth connection.
Another useful additional function is that the PRO has two independent DDS generators, one associated with each port. They can be programmed to use as separate programmable test oscillators.
The Mini-VNA and PRO are of German origin and marketed by Wimo: http://www.wimo.com/cgi-bin/verteiler.pl?url=instrumentation_e.html&p=mi... http://www.wimo.com/cgi-bin/verteiler.pl?url=instrumentation_e.html&p=minivna-more-e#minivna. There is a nice writeup on the original Mini-VNA in the British magazine Practical Wireless (http://www.wimo.com/download/testreport_minivna_practical_wireless-dec-07.pd...) that describes use of the VNA.
73, Tom K3IO