140-0000-973 Emerson Network Power, 140-0000-973 Datasheet - Page 9

• Manufacturer Part Number: 140-0000-973
• Description: CONN JACK SMA END LAUNCH FIXTURE
• Manufacturer: Emerson Network Power
• Series: SMAr

Specifications of 140-0000-973

• Accessory Type: End Launch Connector
• Product: Crimping, Stripping & Cutting Tools & Drills
• Description/function: Soldering Mating Fixture for SMA Jacks
• For Use With/related Products: SMA Jacks
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Lead Free Status / RoHS Status: Not applicable / Not applicable, Lead free / RoHS Compliant
• Other names: J10081

Emerson Network Power • Tel: [phone] • Fax [phone] • www.EmersonNetworkPower.com/connectivity
Low VSWR and Insertion Loss over a Wide Bandwidth
An accurate characterization of packaged microwave circuits, such as broadband MMIC power
amplifiers, requires coaxial to planar transitions with low return and insertion loss. In order to achieve
low loss, the transition design between the launch connector and the printed circuit board requires the
optimization of both mechanical and electrical features. The mechanical design must physically match
the electromagnetic field distribution as close as possible in order to keep the discontinuity reactances
small, as shown in Figure 1. The electrical design must match the impedances and other interface
discontinuity reactances over the entire bandwidth.
Minimizing the discontinuity reactances is desired rather than just compensating for them.
Compensation can limit the usable frequency range of the connector, if the reactances are too large.
The connector design incorporates an internal matched impedance transition from a large input coaxial
connector interface, such as SMA, to a small coaxial output matched to the size of the PC board high
frequency substrate. The internal transition between the input and output consists of graduated
coaxial diametrical step sections, each optimized in size with inductive offsets to reduce the capacitive
discontinuities created by the change in coaxial diameters. As shown in Figure 1, using multiple coaxial
step sections to match the size of the circuit board reduces the overall effect of the discontinuities,
thereby increasing the usable frequency range of the launch connector.
The transition between the launch and the PC board is designed for attachment to grounded coplanar
waveguide (GCPW) transmission lines. The signal output pin of the launcher is optimized in both length
and diameter to match the corresponding GCPW line. The geometrical size of the signal side ground
leg pairs is optimized in height, length and center to center spacing to match the output pin and GCPW
line. The combination of optimal signal pin and ground leg design minimizes the attachment
discontinuity reactance.
Figure 1 - Simulated Electric Field Distributions within the Dielectric Regions at 18 GHz
High Frequency SMA End Launch Connectors
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