RF Circuit Loopback Path for Internal Calibration
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Solution Overview
Problem
Electronic devices using ultra-high frequency bands for wireless communication face challenges in internal calibration due to limited mounting space and the need for external members or measurement equipment, which can be absent, necessitating a loopback path for calibration.
Innovation Solution
The electronic device incorporates multiple electrical paths to form a loopback path using non-used paths, with a wireless communication circuit that includes a source RF circuit and two RF circuits positioned closer to each antenna element, allowing for internal calibration without external members or equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an external member (e.g., waveguide) or measurement equipment is used to perform internal calibration, then calibration can be performed, but the device cannot perform calibration when these external components are absent
Solution Approach 1:
The electronic device performs self-calibration by forming a loopback path using its own internal electrical paths. The calibration signal is generated within the device and routed back to the transmitting RF circuit through receiving RF circuits and connection members, eliminating the need for external calibration equipment.
Solution Approach 2:
Connection members (coaxial cables or FPCBs) serve as intermediaries to establish the loopback path between transmitting and receiving RF circuits. These internal connection members enable the calibration signal to traverse through the device's own components without requiring external waveguides or measurement equipment.
2Reliability
If a connection member is used to connect transmitting and receiving RF circuits for calibration, then internal calibration can be performed, but mounting space becomes deficient due to attenuation of RF performance and size of the connection member
Solution Approach 1:
The patent uses electrical paths that replicate or copy the signal transmission characteristics of external waveguides but in a miniaturized form suitable for internal mounting. The connection members create virtual waveguide paths within the device housing, providing calibration functionality without the space requirements of physical waveguide structures.
Solution Approach 2:
The patent transitions from three-dimensional waveguide structures to two-dimensional electrical paths on circuit boards or coaxial cables routed through the device interior. This dimensional transformation allows calibration functionality to be achieved with significantly reduced mounting space while maintaining electrical performance.
Data Source
AI summary
An electronic device according to various embodiments of the present invention can comprise: a housing; a first antenna element positioned inside the housing or at a first position thereof; a second antenna element positioned inside the housing or at a second position separated from the first position thereof; and a wireless communication circuit positioned inside the housing and electrically coupled to the first antenna element and the second antenna element. The wireless communication circuit comprises: a wireless modem; a source RF circuit electrically connected to the wireless modem, and configured to generate an IF signal; and a second RF circuit positioned at a fourth position closer to the second position than to the first position, wherein: each of the first RF circuit and the second RF circuit is configured to alternately receive an IF signal for transmitting a transmitted signal via the first antenna element and the second antenna element, and includes a first electrical path between the source RF circuit and the second RF circuit, a second electrical path between the source RF circuit and the second RF circuit, and a third electrical path between the first RF circuit and the second RF circuit; the first RF circuit, while being electrically blocked from the first antenna element, is configured to form at least a portion of a first loopback path from the first RF circuit to the source RF circuit through the third electrical path and the second electrical path; and the second RF circuit, while being electrically blocked from the second antenna element, can be configured to form at least a portion of a second loopback path from the second RF circuit to the source RF circuit through the third electrical path and the first electrical path. Additional other embodiments are also possible.