RF Connector PCB Integration Reduces Passive Intermodulation
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Solution Overview
Problem
Existing antenna systems face challenges in minimizing passive intermodulation (PIM) and achieving efficient radio frequency (RF) communication, particularly in wireless communication systems, due to poor galvanic contacts and nonlinear effects caused by passive components, leading to interference and reduced performance.
Innovation Solution
The design incorporates a radio frequency (RF) connector with conductive arms providing thermal relief and a center pin isolated from the conductive body, which is soldered to a printed circuit board (PCB) to achieve a low PIM rating, and an omni-directional antenna system with half and full-wavelength dipole elements on a single PCB, along with a radome to enhance the radiation pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If coaxial RF connectors are used to connect antennas and cables, then mechanical fastening and shielding are provided, but passive intermodulation (PIM) increases due to poor galvanic contacts and nonlinear effects
Solution Approach 1:
The patent extracts the center pin from the conductive body, isolating it to eliminate galvanic contacts between the center pin and conductive body. This separation removes the source of nonlinear effects and PIM generation, while maintaining necessary electrical connections through controlled impedance traces on the PCB.
Solution Approach 2:
The patent introduces an intermediary approach by using isolated center pin connections through PCB traces rather than direct galvanic contacts. This intermediary connection method reduces PIM by avoiding direct metal-to-metal contacts while still providing the necessary electrical pathway for RF signals.
2Object-affected harmful factors
If traditional RF connectors with coaxial cables are used, then shielding is maintained, but the number of parts increases and assembly complexity increases
Solution Approach 1:
The patent merges the RF connector functionality directly with the PCB by integrating the connector body, center pin, and grounding structures into a single PCB-mounted component. This eliminates the need for separate coaxial cables and external connectors, reducing part count while maintaining shielding effectiveness through integrated ground planes and conductive structures on the PCB.
Solution Approach 2:
The PCB serves multiple functions: it provides the mounting substrate for the antenna elements, acts as the shielding structure through ground planes, provides electrical connections through controlled impedance traces, and integrates the connector functionality. This multi-functionality reduces the overall system complexity by eliminating separate components.
3Adaptability or versatility
If multiple separate antennas are used for different functions, then functional independence is achieved, but device complexity and space requirements increase
Solution Approach 1:
The patent combines multiple antenna functions (omnidirectional WiFi antenna with half and full wavelength dipoles, and directional UMTS antenna) onto a single PCB structure. The PCB integrates multiple antenna elements with different geometries and orientations, allowing multiple communication functions to coexist in a compact form factor while maintaining functional independence through separate feed networks and isolation structures.
Solution Approach 2:
The patent utilizes three-dimensional space on the PCB by arranging antenna elements in different planes and orientations. The omnidirectional WiFi antenna uses horizontal dipoles while the UMTS antenna uses vertical elements, effectively using vertical dimension to separate functions and reduce planar space requirements while maintaining functional independence.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces PIM to better than −140 decibels relative to a carrier, improving the performance of RF communication systems by minimizing interference and enhancing the omnidirectional radiation pattern, thereby increasing the reliability and efficiency of wireless communication.
Implementation Method 1
conductive arms providing thermal relief
Implementation Method 2
omni-directional antenna system with half and full-wavelength dipole elements on a single PCB
Data Source
AI summary
Antenna systems have an RF connector, a PCB dipole antenna, and a radome. The RF connector provides a direct connection to the PCB and limits PIM. An omni-directional WiFi antenna has a pair of horizontal dipole antennas on a PCB having different wavelengths and same frequency. An omni-directional UMTS dual antenna has a vertical arrangement of two independent antennas on a PCB and has a jumper printed circuit board connecting the RF connector to the upper antenna. Corresponding connectors, radomes, and ways of combining antenna elements on a single PCB are also disclosed. A single frequency omnidirectional antenna includes both half and full wavelength dipole elements. A plus-shaped radome enhances the omnidirectional radiation pattern of the enclosed antenna. A jumper printed circuit board allows independent antennas on a single circuit board without the degradation of internal coaxial connections. The connector provides a direct interface with a circuit board to reduce the number of parts and also reduce passive intermodulation.