RF Chain Calculator | 射频链路预算计算器

🔴

Transmitter

TX Power (dBm) = 1.000 W

TX Cable Loss (dB)

TX Antenna Gain (dBi)

EIRP 39.00 dBm = 7.943 W

🟠

Channel

Frequency (MHz) λ = 125.0 mm

Distance (km)

Free Space Path Loss (FSPL) 120.05 dB

Additional Losses (dB) Rain, fading, building penetration, etc.

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Receiver

RX Antenna Gain (dBi)

RX Cable Loss (dB)

Receiver Sensitivity (dBm)

Received Power -63.05 dBm

                        Link Margin
                        26.95 dB
                        ✅ Link OK
                    

📐 Formulas & Reference

EIRP = P_TX - L_cable,TX + G_TX

FSPL (dB) = 20·log₁₀(d) + 20·log₁₀(f) + 32.44
d in km, f in MHz

P_RX = EIRP - FSPL - L_add + G_RX - L_cable,RX

Link Margin = P_RX - Sensitivity

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Radar Parameters

Peak TX Power (dBm) = 1.000 kW

Frequency (GHz)

TX Antenna Gain (dBi)

RX Antenna Gain (dBi)

Target RCS (m²)

Min Detectable Power (dBm)

System Losses (dB)

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Radar Results

                        Maximum Range (Monostatic)
                        — km
                    

EIRP — dBm

One-Way FSPL at Max Range — dB

📐 Radar Range Equation

R_max = [ (P_t·G²·λ²·σ) / ((4π)³·S_min·L) ]^1/4

Monostatic: G_TX = G_RX = G

Bistatic variant uses G_TX·G_RX instead of G²

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Array Configuration

Number of Elements (N)

Element Gain (dBi)

Element Spacing (λ) Typically 0.5λ for no grating lobes

Aperture Efficiency

Frequency (GHz)

System Noise Temp (K)

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Array Results

Power per Element (dBm)

                        Array Gain
                        — dBi
                    

                        EIRP (Total)
                        — dBm
                        = — W
                    

G/T (Figure of Merit) — dB/K

3-dB Beamwidth — °

Array Area — m²

📐 Formulas

Array Gain ≈ η · 4π·A/λ² = 10·log₁₀(η·N·G_el) [if η accounts for element]

G/T = G_array (dB) - 10·log₁₀(T_sys)

EIRP = P_total + G_array

θ₃dB ≈ 0.886·λ / (N·d) [for uniform linear array]

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dBm ↔ mW

Power (dBm)

Power (mW) 1000.000 mW

Power (W) 1.000 W

Power (mW)

Power (dBm) 30.00 dBm

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dBi ↔ dBd

Gain (dBi)

Gain (dBd) 7.85 dBd

Linear Gain 10.00

Gain (dBd)

Gain (dBi) 10.00 dBi

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Frequency ↔ Wavelength

Frequency (MHz)

Wavelength 125.00 mm

λ/4 (Quarter Wave) 31.25 mm

Wavelength (mm)

Frequency 2398.45 MHz

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VSWR ↔ Return Loss

VSWR

Return Loss (dB) 9.54 dB

Reflection Coeff |Γ| 0.333

Mismatch Loss (dB) 0.51 dB

Return Loss (dB)

VSWR 2.00

⚡

Pulse Energy Calculator

Peak Power (kW)

Pulse Width (μs)

PRF / PRF (Hz)

Pulse Energy 10.00 mJ

Average Power 10.00 W

Duty Cycle 0.10 %

Pulse Repetition Interval 1000.00 μs

Max Unambiguous Range 150.00 km

🔋

Capacitor Energy Calculator

Capacitance (μF)

Voltage (V)

                        Stored Energy
                        50.00 J
                    

Charge (C) 0.100 C

Discharge Time to 37% (τ=RC) Enter R to calculate:

Load Resistance (Ω)

Time Constant τ 5.000 μs

Peak Discharge Current 20.00 kA

📐 Formulas

E = ½·C·V²

Q = C·V

τ = R·C

I_peak = V / R