RF Network Control

LimeSDR Mini RF network contains matching networks, RF switches, loopback variable attenuator and two SMA connectors (J1 - TX and J2 - RX) as shown in Figure 6.

Figure 6. LimeSDR Mini v2.2 RF diagram

LMS7002M RF transceiver TX and RX ports has dedicated matching network which determines the working frequency range. More detailed information on LMS7002M RF transceiver ports and matching network frequency ranges is listed in the Table 3.

Table 3. LMS7002M RF transceiver ports and matching networks frequency ranges

RF transceiver port	Frequency range
TX1_1	2 GHz - 2.6 GHz
TX1_2	30 MHz - 1.9 GHz
RX1_H	2 GHz - 2.6 GHz
RX1_W	700 MHz - 900 MHz

RF path control signals are described in the Table 4.

Table 4. RF path control signals

Component	Schematic signal name	I/O standard	FPGA pin	Description
RFSW_TX (SKY13411-374LF – IC3)	RFSW_TX_V1	3.3V	B10	V1 – high V2- low TX1_1 to TX and TX1_2 to ATT, V1 – low V2 – high TX1_1 to ATT and TX1_2 to TX
	RFSW_TX_V2	3.3V	C9
RFSW_RX (SKY13411-374LF – IC3)	RFSW_RX_V1	3.3V	C11	V1 – high V2- low RX_H to RX and RX1_W to ATT, V1 – low V2 – high RX1_H to ATT and RX1_W to RX
	RFSW_RX_V2	3.3V	B11
Variable attenuator	TX_LB_AT	3.3V	C8	High - -40dB, low - -25dB
	TX_LB_SH	3.3V	B8	Attenuator shunting.