Differential Transmitter Arrangement for Balun-Free Antenna Phase Alignment
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Solution Overview
Problem
Existing radio communication systems face challenges in achieving high output power and efficiency due to limitations in CMOS technology nodes, which limit the power of individual power stages in power amplifiers, and the use of single-ended antennas necessitates differential to single-ended conversions that suffer from losses and phase imbalances.
Innovation Solution
A transmitter arrangement that performs differential to single-ended conversion using a 180° phase shift on one differential path with a low-loss transmission-line, eliminating the need for baluns and allowing signal combination in air, thereby reducing losses and improving phase alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a balun is used for differential to single-ended conversion, then conversion is achieved, but power loss and phase imbalance occur
Solution Approach 1:
The invention extracts and eliminates the balun component from the differential to single-ended conversion path. By using a differential amplifier with one output directly connected to an antenna and the other output connected via a transmission line with 180-degree phase shift, the patent removes the need for a balun, thereby eliminating the power loss and phase imbalance issues associated with balun-based conversion.
Solution Approach 2:
The invention introduces a transmission line as an intermediary element between the differential amplifier output and the antenna. This transmission line is configured to provide a 180-degree phase shift, serving as a mediator that enables differential to single-ended conversion without requiring a balun, thus avoiding the losses and imbalances inherent in traditional balun-based approaches.
2Ease of manufacture
If CMOS technology is used for integration, then cost and integration are improved, but power output is limited due to voltage headroom constraints
Solution Approach 1:
The invention merges the differential amplifier and antenna elements into an integrated structure where the amplifier is formed in a semiconductor body and the antenna elements are arranged on a substrate. This integration allows CMOS technology to be utilized for cost-effective manufacturing while the differential-to-single-ended conversion architecture enables higher power output by efficiently combining signals from multiple antenna elements without the power loss associated with traditional conversion methods.
3Area of moving object
If single-ended antennas are used, then antenna size is reduced, but differential to single-ended conversion is required causing phase imbalance
Solution Approach 1:
The invention performs preliminary phase adjustment by configuring the transmission line to provide a 180-degree phase shift before the signals are combined at the antenna. This preliminary action ensures that the phase relationship between differential signals is correctly established before radiation, eliminating phase imbalance issues without requiring complex post-processing or precise manual adjustment.
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
This approach enhances transmitter efficiency by minimizing losses and phase imbalances, enabling higher integration and flexibility in antenna array designs while meeting 5G beamforming requirements.
Implementation Method 1
The first transmission line element is configured such that signals applied to respective inputs of the at least two antenna elements are substantially in-phase with each other
Implementation Method 2
a first transmission line element arranged between at least one of the first and second outputs and the respective one of the at least two antenna elements
Data Source
Figure 1~2A
Figure 2B
Figure 3~4
AI summary
The present invention relates inter alia to a transmitter arrangement (1), in particular for radio communication, comprising at least two antenna elements (31, 32), spaced apart by a defined distance and a differential output amplifier (20) with a first output (21) coupled to a first (31) of the at least two antenna elements (31, 32) and with a second inverted output (22) coupled to a second (32) of the at least two antenna elements (31, 32). A first transmission line element (50) is arranged between at least one of the first and second outputs (21, 22) and the respective one of the at least two antenna elements (31, 32) and is configured such that signals applied to respective input taps (310, 320) of the at least two antenna elements (31, 32) are substantially in-phase with each other.