Signal Design from RF to BB

Signal Design Reference

Domain	Parameter	Range	Configurable	Consideration
Condition	c (Speed of light)	3×10^8 m/s
	F (Noise Figure)	10 dB	fixed by SoC	Noise floor → SNR
	f_s (Sampling Rate)	2.5 MHz	fixed by SoC	Limiting beat frequency to f_nyq
	R_max (Requirment)	0.75 ~150 m	User Configurable	Slope

RF	P_tx (TX Power)	0~ 10 dBm	User Configurable	SNR
	G_t (TX Antenna Gain)	Normally 2~10 dBi	fixed by design	TX power → SNR
	G_r (RX Antenna Gain)	Normally 2~10 dBi	fixed by design	RX power → SNR
	f_start (Start Frequency)	24.00~24.25 GHz	User Configurable	B_RF → Range Resolution
	f_stop (Stop Frequency)	24.00~24.25 GHz	User Configurable	B_RF → Range Resolution
	TX*RX (Antenna Array)	(1~4)*(1~4)	fixed by design
	k (Beam Shape Factor)	Normally 1	fixed by design	Angle Resolution and Precision

Chirp	T_START @min	20 us	Semi-fixed by SoC
	T_UP @min	150 us	User Configurable	Chirp Slope, Beat Frequency
	T_DOWN @min		User Configurable
	T_STOP @min	410 us	Semi-fixed by SoC

Frame	T_PRE	20us	Semi-fixed by SoC
	T_NOP	76 us	User Configurable	Power consumption, Frame rate.
	Chirp Number	32~64	User Configurable	Angle Resolution, Doppler processing gain

1. Example Configuration

Example of Configuration for the basic parameters.

Domain	Parameter	Range	Configuration
Condition	c	3×10^8 m/s	3×10^8
	F	10 dB	10
	fs	2.5 MHz	2.5
	R_max	0.75~ 150 m	8

RF	P_tx	0~ 10 dBm	10
	G_t	10 dBi	10
	G_r	10 dBi	10
	f_start	24.00 ~ 24.25 GHz	24.05
	f_stop	24.00 ~ 24.25 GHz	24.25
	TX*RX (Antenna)	N_t * N_r	1 * 2
	k	Normally 1	1

Chirp	T_START @min	20 us	20
	T_UP @min	150 us	420
	T_DOWN @min	150 us	150
	T_STOP @min	410 us	410

Frame	T_PRE	20 us	20
	T_NOP	76 us	76
	Chirp Number	32~64	32
Target	Human	0.5~1.0 m^2	0.5

2. Derivation of 2nd Parameters.

Derive secondary parameters from the configured basic parameters.

Parameter	Symbol	Calculation Process	Calculated Value
Baseband Bandwidth	B_BB	fs/2, Robust: 30% of fs/2	1.25 MHz, Robust: 375 kHz
RF Chirp Bandwidth	B_RF		200 MHz
Center Frequency	fc	(24.05+24.25)/2	24.15 GHz
Wavelength	λ	c/fc	12.42 mm
Antenna Spacing	d	λ/2	6.21 mm
Receiver Noise Floor	Pn	P_therm + F	-103 dBm
Received Signal Power	Pr	Radar Equation(G_t, G_r to linear value)	−80.23 dBm
Chirp Slope	S	200MHz/420µs	0.476 MHz/µs
Chirp Cycle	T_c	$20 + 420 + 150 + 410$ µs	1,000 us
Frame Cycle	T_f	$20 + (32 \times 1000) + 76$ µs	32.096 ms

3. Calculation of Radar Specification.

Calculate radar specification from basic and derived parameters.

Spec. Domain	Spec. Item	Calculation Process	Calculated Value
Range	R_max	Given	8 m
	ΔR		0.75 m
	σ_r	Variable by Environmental(SNR)	0.043 m
Velocity	V_max		3.11 m/s
	ΔV		0.194 m/s
	σ_v	Variable by Environmental(SNR)	0.011 m/s
Angle	θ_max	d=λc/2	±90°
	Δθ	N=2, d=λc/2	57°
	σ_θ	Variable by Environmental(SNR)	3°