Over on CrowdSupply a new SDR called "uSDR" created by Wavelet SDR has been announced (not to be confused with the uSDR software). uSDR is a tiny SDR that interfaces via an M.2 slot on a PC/laptop motherboard. Typically M.2 slots are what you would use to connect a solid-state drives (SSD), but can also be used for adding expansion cards. However, a simple M.2 to USB adapter could be used to convert it into dongle form.
The uSDR is advertised of being a duplex TX & RX capable SDR, with a frequency range of 300-3700 MHz, and up to 30.72 Msps of sampling rate. It also has a 0.5 PPM TCXO. To keep it's tiny form factor, it uses small MHF4 antenna connectors.
The device appears to be based on the AMD Xilinx ARTIX-7 FPGA and the LimeMicro LMS6002 transceiver IC.
One interesting differentiating feature of the uSDR is that it is designed to be operated via it's web interface which can be accessed through Chrome. They make use of WebUSB technology, which allows Chrome to directly connect to USB devices. This should help eliminate installation and compatibility issues, and allow the SDR to easily be used over a network. Apart from the web interface it is also compatible with SoapySDR and GNU Radio. Sergey, one of the creators of uSDR wrote:
During development we focused on ease of use, thus it supports WebUSB interface. Meaning you can view Spectrogram, record or playback IQ data, do some signal analysis and even share your device over the internet to get others access to it. And all this doesn’t require any software or specific drivers and works in Linux/Windows/Mac OS/Android and more. One can even extend these applications and run their own.
The device is single channel covering a range ~230MHz-3.7GHz for TX / RX and we’re making it affordable. Last but not least you still can use this device with SoapySDR as a regular SDR.
The project is currently in it's early stages, with Crowd Funding expected to begin soon. Pricing is still unknown, however Sergey did mention that it will be affordable. Subscribe for announcements via their CrowdSupply page.