BACL has performed Dynamic Frequency Selection (DFS) testing on a variety of WLAN devices with the National Instrument’s NIPXI-1042 testing system according to the current FCC, EU, Korean, and Japan standards for many notable technology companies.
In keeping up with the DFS requirements, we will continue to offer our clients unparalleled testing capabilities for all DFS regulated markets.
BACL has the capability to performs Hearing Aid Compatibility (HAC) testing for mobile devices, including RF Emissions and T-Coil measurements in accordance with ANSI C63.19-2007.
HAC RF-Emission: The RF measurement requirements for HAC compliance are somewhat similar to SAR measurements. Both HAC and SAR measurements involve closely coupled near-field measurements over the face of the wireless device (WD) with a moving probe controlled by a robotic device.
Testing for HAC compliance,
the measurements for peak field strength are made in air and not through the tissue simulant fluid that is used when testing for SAR compliance. HAC testing also requires separate scans of the E (electric) and H (magnetic) field components, whereas for SAR testing, the power density is calculated by measurement of the E-field component. The E and H field HAC probes have an isotropic response and are calibrated in accordance with IEEE 1309.
Electric and Magnetic Field Category Rating Table:
|Category||Hearing Aid Parameters
(Hearing Aid must maintain < 55 dB IRIL interference level and < 6 dB Gain Compression)
|Category U1||30.0 – 35.0 dB (V/m)||-23.0 – -18.0 dB (A/m)||6 – 51 dB(V/m) + 0.5 x AWF||-4.4 – 0.6 dB(A/m) + 0.5 x AWF|
|Category U2||35.0 – 40.0 dB (V/m)||-18.0 – -13.0 dB (A/m)||41- 46 dB(V/m) + 0.5 x AWF||-9.4 – -4.4 dB(A/m) + 0.5 x AWF|
|Category U3||40.0 – 45.0 dB(V/m)||-13.0 – -8.0 dB (A/m)||36 – 41 dB(V/m) + 0.5 x AWF||-14.4 – -9.4 dB(A/m) + 0.5 x AWF|
|Category U4||>45.0 dB (V/m)||>-8.0 dB (A/m)||<36 dB(V/m) + 0.5 x AWF||<-14.4 dB(A/m) + 0.5 x AWF|
HAC T-Coil: Wireless Device’s T-coil performance is required in the HAC specification. For this, care must be exercised to separate the desired audio band magnetic signal emanating from the WD, from the undesired magnetic interference generated by incidental circulating currents in the WD’s circuits. For these T-coil measurements, two special probes have been designed to respond separately to the axial and transverse components of the magnetic field. The probes, no more than 10mm in diameter, contain tiny coils made up from more than 20 of ultra-fine (51 AWG) copper wire. The raw signals they detect must be amplified and filtered by specialized audio equipment to ensure the levels are completely unaffected by outside influences.
T-Coil Category Rating Table:
|MAGNETIC COUPLING PARAMETERS|
|Category||Hearing Aid Parameters||Telephone Parameters|
|Near Field Immunity
(w/ 27.8 dBm CW into Dipole)
|WD Signal Quality
(Signal+Noise-to-Noise Ratio in dB)
|Category U1T||75 – 85 dB(IRIL)||-10 – -20 dB + AWF|
|Category U2T||65 – 75 dB(IRIL)||0 – -10 dB + AWF|
|Category U3T||55 – 65 dB(IRIL)||10 – 0 dB + AWF|
|Category U4T||<55 dB(IRIL)||>10 dB + AWF|
(NOTE: A comparable hearing aid immunity test can be performed by fixing the acoustic output power requirement at 75 dB(IRIL) for all categories and varying the power into the dipole from 22.8 dBm for category U0, increasing by +5 dB for each higher category.)