Wideband Driver Amplifier With Embedded CLC Filtering for Harmonic Rejection
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Solution Overview
Problem
Existing harmonic rejection mixer (HRM)-based architectures for TV-band transmitters face challenges in achieving wideband operation while managing high-frequency reference local oscillators (LOref), leading to power consumption and complexity issues, as well as insufficient harmonic rejection ratio (HRR) across a broad RF range.
Innovation Solution
A wideband driver amplifier design incorporating a two-stage 6P-HRM or 14P-HRM configuration combined with passive band-selection filtering, which reduces the LOref frequency and enhances HRR by using low Q passive-RC/-CLC filters, thereby simplifying the LO generation and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-frequency reference LO (LOref) is used in HRM-based architectures to achieve precise harmonic rejection, then HRR is improved, but power consumption and device complexity increase
Solution Approach 1:
The LO generation is segmented into multiple frequency ranges (first frequency range and second frequency range). The system uses a first LO for lower frequencies and a second LO for higher frequencies, avoiding the need for a single high-frequency reference LO across the entire bandwidth. This segmentation reduces power consumption while maintaining HRR performance in each respective band.
Solution Approach 2:
The system dynamically switches between different LO configurations based on the operating frequency range. A switching mechanism selects appropriate LO paths (first LO or second LO) depending on whether the RF signal is in the lower or upper frequency range, optimizing power consumption and HRR performance adaptively across the wide bandwidth.
2Adaptability or versatility
If high-frequency reference LO (LOref) is used to extend operating bandwidth, then RF range is improved, but device complexity increases
Solution Approach 1:
The wideband operation is achieved by segmenting the frequency range into two bands, each handled by a dedicated LO configuration. This avoids the complexity of generating a single high-frequency reference LO that would be required to cover the entire wide bandwidth, simplifying the frequency synthesis architecture.
Solution Approach 2:
The first LO and second LO are designed to be universal solutions for their respective frequency ranges. The first LO handles lower frequencies with adequate HRR, while the second LO handles higher frequencies, providing a universal approach to maintaining performance across the entire wideband operating range without requiring a complex high-frequency reference.
3Use of energy by moving object
If passive band-selection filtering is used to reduce LOref frequency, then power consumption is improved, but filtering precision may be affected
Solution Approach 1:
The patent merges passive band-selection filtering with the driver amplifier stage, integrating the filtering function directly into the amplification path. This combination allows the use of lower Q (and thus lower power) passive filters while maintaining adequate filtering precision through the synergistic effect of the amplifier's inherent characteristics and the passive filter's frequency selectivity.
Data Source
AI summary
A wideband driver amplifier with embedded passive filtering and gain peaking is described. The wideband driver amplifier comprises a voltage to current circuit, a passive band-selection filter, and a current to voltage circuit. The driver amplifier features an Embedded CLC-Ladder band-selection filter and thereby immune to process variations.