Why the receiving current is greater than the sending current for DW1000?
In an UWB RF system the receiver has to pull the very low RX signal levels out from below the noise floor. This requires significant RF/IF gain and digital DSP processing power (hence current).
The flip side of this is that the TX is quite power efficient, as we are just sending very short pulse sequences which require little computational effort to calculate. Most of the TX current is in the RF output stage where we drive the pulses in to the antenna load.
The DW1000 datasheet block diagram (fig 1 in the datasheet) will help explain why RX current is higher than TX. As you can see the RX current is spread across RF PLL, RX IF strip and digital part, while TX current consumption is mainly the RF PLL and TX amp.