A sensor interface circuit includes: an RF switch having a control node; a bias circuit electrically connected to the control node and applying, to the control node, a voltage at a first level or a second level corresponding to a linear region of a reflection characteristic; a first variable oscillation circuit electrically connectable to a first sensor; a second variable oscillation circuit electrically connectable to a second sensor; and a difference circuit electrically connected between the first variable oscillation circuit and the bias circuit, and between the second variable oscillation circuit and the bias circuit.

Tunneling field effect transistors and fabrication methods thereof are provided, which include: obtaining a gate structure disposed over a substrate structure; and providing a source region and a drain region within the substrate structure separated by a channel region, the channel region underlying, at least partially, the gate structure, and the providing including: modifying the source region to attain a narrowed source region bandgap; and modifying the drain region to attain a narrowed drain region bandgap, the narrowed source region bandgap and the narrowed drain region bandgap facilitating quantum tunneling of charge carriers from the source region or the drain region to the channel region. Devices including digital modulation circuits with one or more tunneling field effect transistor(s) are also provided.