What's a reference text on analog design?
The book I learned from, and that I still see new hires bringing with them from school was Grey & Meyer (now Grey, et al.), Analysis and Design of Analog Integrated Circuits. This was the text in the main analog design course at Berkeley in the '90's, and I believe it's also used at numerous other institutions. It's got as much theory as they teach undergrads anywhere in the country. Of the topics you expressed specific interest in, this book does cover current mirrors, differential stages, and feedback theory. It also has a very quick chapter on device models of diodes, BJTs and MOSFETs. It doesn't go particularly deeply into device physics -- only enough to motivate the models.
On the other hand, its heavily aimed at future IC designers, and at CMOS op-amp designers, which implies a whole different set of design techniques than you'll use building analog circuits from discrete components or op-amp ICs.
For board-level circuit design, app notes from the various vendors are probably as good as any textbook. For example, TI's Op Amps for Everyone, or Analog's Op Amp Applications Handbook. Even if these guides will tend to recommend a particular vendor's products, they do provide a strong background in theory that applies to using any vendor's parts, and they do provide a good balance between theory and practical issues. You haven't stated what you mean by "wideband" applications, but op amps are available off the shelf with gain-bandwidth products above 1 GHz, so these op-amp-focused books may apply better than you think.
As The Photon says, Gray and Meyer is the go-to reference for analog, but IMO it's a hard nut to crack if you're just starting out. You probably want an intermediate text, and any text that's used at a university with a respectable engineering program is a likely choice. The standard, which I have no experience with, is probably Sedra & Smith. The class I took used Howe & Sodini, which has mixed reviews, but I thought it was a reasonably good book at the time. It covers the basic analog building blocks and has some device physics, and though I have no direct experience with other texts in this category, they should all cover the same ground.
[A personal preference: Depending on your learning style, you may want to consider getting several books. By getting older editions (big-picture analog concepts don't really change) you can end up spending less money overall, and get multiple takes on the subject.]
Also consider using lecture materials from courses posted on the web, such as those at MIT (6.012, 6.301) and UC Berkeley (EE105, EE140, EE240).
Possible intermediate texts, culled from syllabi:
- Howe and Sodini, Microelectronics: an Integrated Approach
- Sedra and Smith, Microelectronic Circuits
- Jaeger, Microelectronic Circuit Design
- Horenstein, Microelectronic Circuits and Devices
- Spencer and Ghausi, Introduction to Electronic Circuit Design
- Razavi, Fundamentals of Microelectronics
- Neamen, Microelectronics: Circuit Analysis and Design