{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://www.calculatorx.com/schemas/electrical.rf.antenna_length/1.0.3/input.json",
  "title": "Antenna length — input",
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "mode": {
      "type": "string",
      "enum": [
        "half",
        "quarter",
        "wavelength"
      ],
      "default": "half",
      "description": "Requested antenna fraction. half = λ/2 dipole total length; quarter = λ/4 monopole radiator over ideal image plane; wavelength = corrected 1λ length L = k·λ₀ (equals free-space λ₀ only when k=1)."
    },
    "f_Hz": {
      "type": "number",
      "exclusiveMinimum": 0,
      "description": "Operating frequency in hertz. Must keep λ₀ and L finite in IEEE-754 binary64."
    },
    "length_factor": {
      "type": "number",
      "exclusiveMinimum": 0,
      "maximum": 1,
      "default": 1,
      "description": "Empirical length/shortening factor k for the physical element. 1.00 is ideal free-space fractional wavelength. Not a transmission-line velocity factor. Practical resonant wire antennas are often ~0.95 due to diameter, end effect, insulation, and surroundings."
    },
    "velocity_factor": {
      "type": "number",
      "exclusiveMinimum": 0,
      "maximum": 1,
      "deprecated": true,
      "description": "Deprecated alias of length_factor. Prefer length_factor. Kept for URL/API compatibility; must match length_factor when both are sent."
    }
  },
  "required": [
    "f_Hz"
  ],
  "description": "λ/2 dipole total length · λ/4 monopole radiator · corrected 1λ (k·λ₀) from frequency and empirical length factor k. (calculation_version 1.0.3)"
}