I agree with IanB. First learn about RF.
1 mHz = 1 milliHerz, You prabably mean 1 MHz (MegaHerz)
1 MHz is almost audio. You need big coils and capacitors, for 2.5 GHz (not ghz) you use microstrip or stripline or other plumbing like constructions.
Because you talk about swr meter you probably thinking about transmitters. For transmitters you need other gear as for receivers.
I do a lot of RF.
You need:
- A very good knowledge about basic electronics and components.
- a good knowledge about wave theory (things like reflections, propagation, delay, phase, transmissionlines etc)
- Good books about RF like the book from Hayward as mentioned befor, RF circuit design of Bowick, And handbook of microwave component measurements from Dunsmore, AC theory from Knight (free to download pdf)
Gear I use most:
- Spectrum analyser,
- Vector Network analyser with the right fixtures (this also gives you swr, but in RF design we most times talk about rho or return loss), a VNA can be replaced with a spectrum analyser with tracking generator and directional couplers and bridges for most things)
- directinal couplers for high frequencys and a directional bridge for a few hundered MHz.
- good calibration kit.
- Fixed inline Attenuators and switchable ones in 1 dB and 10 dB steps
- inline probeadapter
- probeadapters to solder to the pcb
- something like a sniffer antenna for the SA and H-field probes to couple the signal to the SA when using higher power
- trimmerset
- shielding material if you want to build stuff, and lots of sma, bnc and N chassismount connector. A crimper for coannectors to cable.
- for transmitters a good dummyload
- a high bandwidt scope (My DSO is 350 MHz but I have sample scopes upto 5 GHz and often use a max 3000 MHz scope downconverter.
- good high bandwidt 10X, 50 Ohm Zo, and active probes
- inline terminators
- A lot of good RF coax cables (not the chinese ext ethernet bnc stuff but stick to amphenol or radial with something like belden cable
- Good quality adapters from bnc to sma, N, PL, smb etc end the otherway around
- A good LCR meter
I probably forget some stuff. But most important for me are a VNA, SA, LCR (meter and bridge) and scope
But all depends on what you want to build .