Equipment Under Test (EUT) Description
The equipment under test (EUT) is a transmitter for a Volvo My First RC, operating at 27.145 MHz and controlled by a crystal. The EUT is powered by two 1.5V AAA batteries. For more detailed information, please refer to the user manual.
Technical Specifications
Antenna Type: dedicated antenna
Antenna Gain: 0dBi
Modulation Type: Pulse modulation
Nominal Conducted Output Power: -20.0dBm (+/- 3dB)
Nominal Radiated Output Power (e.r.p): -22.15dBm (+/- 3dB)
Compliance Analysis (KDB 447498)
According to the KDB 447498:
- The worst-case peak radiated emission for the EUT is 74.7 dBuV/m at 3m in the frequency 27.145MHz.
- The EIRP = [(FS*D)^2 / 30] mW = -20.53dBm
- The ERP = EIRP – 2.15 = -22.68 dBm, which is within the production variation.
The maximum conducted output power specified is -17dBm, equivalent to 0.02mW.
The source-based time-averaging conducted output power is calculated as 0.02 * Duty Cycle mW, which must be less than 0.02mW (Duty Cycle < 100%).
SAR Exclusion Threshold
The SAR Exclusion Threshold Level for 27.145MHz, when the minimum test separation distance is less than 50mm, is determined by the formula:
Calculation: 474 * [1 + log(100/f(MHz))]/2
Result: = 371.2 mW
Since the source-based time-averaging conducted output power is well below the SAR low threshold level, the EUT is considered to comply with SAR requirements without further testing.
Transmitter Duty Cycle Calculation
The duration of one cycle is 48.493ms.
The effective period of the cycle is calculated as: 1.522ms x 4 + 507.0μs x 40 = 26.3680ms.
The Duty Cycle (DC) is: 26.3680ms / 48.493ms = 0.5437, or 54.37%.
FCC Information
FCC ID: PKG17112RC27
