Figure 6: Functional block diagram
(left) and photograph (right) of RTL-SDR.
It gets its RF functionality from Rafael Microelectronics make R820T
chip. R820T is a RF tuner IC which consists of a mixer and digitally
controlled VCO along with variable gain amplifier and filter stages
before and after the mixer stage. VCO oscillator frequency, amplifiers
gain and filter bandwidth of R820T are controlled by the Realtek
RTL2832U chipset over I2C serial bus. RTL2832U also digitize the down
converted baseband IF signals using inbuilt DDC and sends 8 bit IQ data
over USB bus to the PC for further processing. Key specifications of
RTL-SDR are tabulated in Table 5. More details of RTL-SDR hardware can
be obtained from [1].
Table 5: RTL-SDR Specifications