python HF 13.56 detuning and fix simulation calculator

gistfile1.txt

import numpy as np

def calculate_rfid_performance():
    print("\n--- 13.56 MHz RFID/FeliCa Range & Tuning Calculator ---")
    print(" (Press ENTER to accept the default values in brackets) \n")
    
    # 1. Antenna Geometry
    a_input = input("Enter antenna side length in mm [Default: 80]: ").strip()
    a = float(a_input if a_input else 80) / 1000.0  # convert to meters
    
    N_input = input("Enter number of antenna turns [Default: 3]: ").strip()
    N = int(N_input if N_input else 3)
    
    I_input = input("Enter antenna drive current in Amps [Default: 0.2]: ").strip()
    I = float(I_input if I_input else 0.2)
    
    # 2. Environment Constraints
    z_input = input("Enter target compliance read distance in mm [Default: 70]: ").strip()
    z_target = float(z_input if z_input else 70) / 1000.0
    
    m_input = input("Enter side metal gap in mm [Default: 25]: ").strip()
    metal_gap = float(m_input if m_input else 25) / 1000.0
    
    # 3. Ferrite Properties
    use_ferrite = input("Are you using ferrite tape? (yes/no) [Default: no]: ").strip().lower()
    if use_ferrite == 'yes' or use_ferrite == 'y':
        mu_input = input("Enter ferrite real permeability mu' at 13.56 MHz [Default: 100]: ").strip()
        mu_prime = float(mu_input if mu_input else 100)
    else:
        mu_prime = 1.0  # Air/Vacuum permeability
        
    # Physical Constants
    mu_0 = 4 * np.pi * 1e-7  # Permeability of free space
    
    # --- Part 1: Ideal Magnetic Field B(z) at Target Distance (Biot-Savart Law) ---
    numerator = mu_0 * I * N * (a**2)
    denominator = np.pi * ((a/2)**2 + z_target**2) * np.sqrt(2 * (a/2)**2 + z_target**2)
    B_ideal = numerator / denominator
    
    # --- Part 2: Metal Interaction & Eddy Current Losses ---
    # Coupling factor increases exponentially as the gap gets smaller relative to antenna size 'a'
    coupling_factor = (a / (2 * metal_gap))**3 if metal_gap > 0 else 100
    
    # High mu' ferrite drops the shielding effectiveness factor, reducing opposing eddy current fields
    shielding_effectiveness = 1.0 / mu_prime
    loss_coefficient = 0.15 * coupling_factor * shielding_effectiveness
    
    # Calculate final effective B-field factor (bounded safely between 0.1 and 1.0)
    field_retention = max(0.1, min(1.0, 1.0 - loss_coefficient))
    B_effective = B_ideal * field_retention
    
    # --- Part 3: Calculate Estimated Read Ranges ---
    # Benchmark open-air range (roughly 95% of antenna loop size for high-performance readers)
    open_air_range_mm = a * 1000 * 0.95 
    # Read range scales down with the cube root of the field attenuation
    current_range_mm = open_air_range_mm * (field_retention ** (1/3))
    
    # Output Report
    print("\n=================== RESULTS ===================")
    print(f"Ideal Forward B-Field (Open Air):  {B_ideal*1e6:.2f} uT")
    print(f"Effective B-Field (With Metal):   {B_effective*1e6:.2f} uT")
    print(f"Field Energy Retention:           {field_retention*100:.1f}%")
    print("-----------------------------------------------")
    print(f"Estimated Read Range:             {current_range_mm:.1f} mm")
    
    if current_range_mm >= (z_target * 1000):
        print("COMPLIANCE STATUS:                PASSED ✅")
    else:
        print("COMPLIANCE STATUS:                FAILED ❌")
    print("===============================================\n")

if __name__ == "__main__":
    calculate_rfid_performance()