ANSI 125-2011 pdf download Hard Line Pin Connector Return Loss
1.0 SCOPE AND DEFINITIONS
1.1 This document describes a procedure to measure the Return Loss characteristics of a single Hard Line Pin Connector interfaced between (1) hard line cable and a precision airline. It implements the time domain-gating features of the network analyzers, which removes the interfaces, and far end termination from the DUT (device under test) measurement.
1.2 Definitions
a. Gating: Technique for selectively removing the response of a non-perfect connector from return loss measurements.
b. Directivity: The figure of merit for how well a directional coupler separates forward and reverse waves. The greater the directivity of the device, the better the signal separation. System directivity is the vector sum of all leakage signals appearing at the analyzer receiver input. The error contributed by directivity is independent of the characteristics of the test device and it usually produces the major ambiguity in measurements of low reflection devices.
c. Return Loss: The ratio of incident signal to reflected signal, expressed in dB.
d. Network Analyzer: An instrument for measuring the swept frequency response of a cable or cable/connector combination.
2.0 EQUIPMENT
2.1 Vector Network Analyzer (VNA), with Time Domain capability: Agilent8753ES with options 010 (time domain) and 075 (75 ohm ports), or equivalent.
2.2 Type “N” 75-Ohm Calibration Kit; Agilent 85036B, or equivalent.
2.3 Flexible Precision Test Cables; Type “N”, 75 Ohm.
2.4 5/8-24 female to “N”male, Precision Adapter, Return Loss, ≥ 40 dB.
2.5 Hard line cable that meets the requirements of ANSI/SCTE 15 2006, 75 Ohm,length, 15 inches ±1/2 inch; cable size matches that of pin connector being tested.
2.6 5/8-24 female precision airline, Return Loss, ≥ 40 dB. See Airline Adapter Drawings in Section 8.0.
2.7 5/8-24 male to “N”male, Precision Adapter, Return Loss, ≥ 40 dB.
3.0 SET-UP
3.1 Vector Network Analyzer
3.1.1 Allow equipment to warm up per manufacturer’s instructions.
• Preset
• IF Band Width = 3000 Hz
• Dual Chan = ON; Split Display = ON
• FORMAT – CH 1 = Log Magnitude; CH 2 = Real
• START = 5 MHz; STOP = 3 GHz
• Number of Points = 801
• Set CH1 & CH2 to S11
• SYSTEM – Transform -Low Pass Step
• Set frequency Low Pass