The is a low profile, miniature 3dB hybrid coupler in an easy to use surface mount package designed for AMPS applications. The 1C403 is designed for balanced amplifiers and signal distribution and is an ideal solution for the ever-increasing demands of the wireless industry for smaller printed circuit boards. Parts have been subjected to rigorous qualification testing and units are 100% tested. They are manufactured using materials with x and y thermal expansion coefficients compatible with common substrates such FR4, G-10 and polyamide.
MHz High Power Very Low Loss High Isolation 90o Quadrature Surface Mountable Tape and Reel Convenient Package 100% Tested Frequency
**Specification based on performance of unit properly installed on microstrip printed circuit boards with 50 nominal impedance. Specifications subject to change without notice.
Top View (Near-side).354�.010 [9.0�0.25] Pin 4 Pin 3.110�.011 [2.80�0.28] Pin 3 Side View Bottom View (Far-side) 4X.032�.004 [0.81�0.10]Available on Tape and Reel For Pick and Place Manufacturing.
AMPLITUDE BALANCE 3dB hybrids are a type of backward wave coupler. In the design of these couplers, the even mode impedance was chosen to `critically couple' or slightly `over couple' at mid band to maximize performance and bandwidth. The amplitude balance specification is defined as the decibel difference between the two output curves. PHASE BALANCE In theory, output ports of a backward wave hybrid coupler remain in perfect phase quadrature independent of frequency. In practice, factors associated with the manufacturing processes slightly degrade performance. The specification is typically two to three degrees maximum. In practice, phase is statistically better than the specified value (<1o).
VSWR & ISOLATION Similar to phase balance, the VSWR and isolation of a coupler are theoretically perfect; where the input and output ports are perfectly matched and no power is coupled to the isolated port. In practice, factors associated with the design and manufacturing processes limit VSWR and isolation. The significant limitations are associated with limitations of building perfect 50 transitions at the input and output ports of the device. INSERTION LOSS Coupler insertion loss is defined as the difference of the input power from the sum of the output power. In practice, loss is typically 0.20 dB. Specification limits are somewhat higher due to imperfect test conditions; as the couplers must be tested in fixtures that negatively affect results.
PIN CONFIGURATION When a surface mount hybrid coupler is mounted to a printed circuit board, the primary concerns are; ensuring the RF pads of the device are in contact with the circuit trace of the PCB and insuring the ground plane of neither the component nor the PCB is in contact with the RF signal. As long as the geometry of the unit fits onto the layout of the circuit trace on the PCB, and the conditions of the previous paragraph are followed, the coupler's performance is ensured. An example of how the PCB footprint could look is shown below. In specific designs, the 50 lines need to be adjusted to the unique dielectric coefficients and thicknesses as well as varying pick and place equipment tolerances. To ensure proper electrical and thermal performance there must be a ground plane with 100% solder connection underneath the part. SUGGESTED FOOTPRINT
To ensure proper electrical and thermal performance there must be a ground plane with 100% solder connection underneath the part
The 1C403's have an orientation marker to denote the topside of the part. The part however can be rotated about the z-axis so that any pin can be used as the input port as described by the chart above. MOUNTING In order for Xinger surface mount couplers to work optimally, there must be 50 transmission lines leading to and from all of the RF ports. Also, there must be a very good ground plane under the part to ensure proper electrical performance. If either of these two conditions are not satisfied, insertion loss, coupling, VSWR and isolation may not meet published specifications. Overall ground is improved if a dense population of plated through holes connect the top and bottom ground layers of the PCB. This minimizes ground inductance and improves ground continuity. All of the Xinger hybrid and directional couplers are constructed from ceramic filled PTFE composites that possess excellent electrical and mechanical stability having X and Y thermal coefficient of expansion (CTE) of 17 ppm/oC.Multiple plated thru holes to ground 4X 50 Transmission Line