Analog field can be broadly classified into 3 segments
This comprises of designing wireless circuits like LNAs (Low Noise Amplifiers), PAs (Power amplifiers), mixers, oscillators, PLLs etc. with narrow band high-Q circuits.
This comprises of designing broadband analog circuits. These circuits deals with the interface ICs like high speed SerDes, data converters, precision op-amps, filters, band gap reference circuits, oscillators, PLLs etc.
In this category, power management IPs like voltage regulators, DC-DC converters, band-gap circuits, low drop out regulators, battery chargers etc. are dealt with.