In experimental physics it is required to use electronics as instruments. You must know how they work(amplifiers, ADC's, MCA's etc) in order to fully understand and design an experiment.
Usually, you don't need too much electronics(filters, amplifiers, transistors, digital electronics-boolean algebra) is more often than not, more than enough.
You need electronics in read out systems or trigger systems. But you need it in a know-how way rather that very deeply.
The field that understands and develops such ideas, is
Microelectronics which can be an Applied Physics expertise.
However, the phenomena that build the eelctronics we know are pure electromagnetism! Actually, Farraday, Ampere et al(!) observed the bahaviour of simple electronic devices(such as capacitors). I have always been saying that electronics is Applied Electromagnetism!
As far as out universe awareness is concerned, electronics really help you understand the universe;in a indirect way, however. Great experiments(ATLAS, CMS, DELPHI, HERA, etc) have spent great money and time to build fancy electronic systems. The basic idea is to design trigger and read out, and tell the either the engineers or the MicroElectronic's Physicists to build them! Also NASA's and ESA's missions, can't live without electronics that are radiation hard! So it is a means, rather than a basic reasearch on electronics.
But when it comes to great experiments and large collaborations, sometimes the physicist becomes an engineer, from the pint of view of the electronics. In detector physics for instance, I know a lot of guys tha are physicists, but work on electronics, such us FPGA design, trigger logic etc