Design RF circuit / product

I need a design/schematic and working prototype (or instructions to breadboard it). Essentially I need an RF receiver that works between 148-152mhz, scans for an active signal across that range, and when it picks up a signal, it will output it to a 3.5mm jack so the signal can be recorded on a mobile phone. Ideally it will be powered by (possibly) a mobile phone usb port (not sure if they provide outward voltage), a small solar panel or some other small, maintainable and long-lasting power supply (with an option to have a DC power source from main power). Now for the (potentially) tricky part - when the signal is sent to the mobile phone, the signal must be augmented with an indicator of the frequency on which it was found. The signals only last about 200-300ms so you can squeeze in before or after that. The outbound signal must be able to be interpreted by software once it is recorded. The product size should be small enough to attach to the back of a mobile phone (velcro). If the prototype works we would look to have a second round of design for tweaking/enhancement and then manufacturing an initial run.