Re: 2MHz antenna
Well, 2 mhz might be a good frequency if it is actually implanted inside of a body. About the highest I might go with such a system is 8 MHz. Much higher and the salty flesh of the body will stop signals from penetrating out.
You will have a lot of trouble radiating from an antenna, since a quarterwave at 2 MHz is thousands of times too big for your application. I would print an on-chip inductive loop around the periphery of your IC chip, and drive it with a current source transmitter. Properly done, the current source transmitter might run off of a very low voltage supply, like maybe 1.2V dc. The transmitter loop would NOT be resonated at 2 MHz.
Then I would use a much larger receiver loop antenna, with lots of turns and tuned to that 2 MHz frequency. Maybe a 2 foot by 2 foot receiver loop? That should get you a few feet of transmission range.