Innowave Low Noise Amplifier Design: Measurement Details Needed

mounasumamandava wrote:

(...) gain, noise figure, input/output impedance)?
gain , q factor , noise figure , input / output impedences , inductor ,capacitor , resistor values also
AI: Could you provide the link or more context about the reference you mentioned in your post?
https://innowave.co/2022/11/29/low-noise-amplifier-design/

Initial Assessment of Available Information
You have requested specific measured parameters and component values (gain, Q factor, noise figure, input/output impedances, inductors, capacitors, resistor values) from the Low Noise Amplifier (LNA) design discussed at the Innowave link:
https://innowave.co/2022/11/29/low-noise-amplifier-design/

From the sample answers provided, there is some inconsistency: one answer presents specific inductor and capacitor values, while another indicates that the Innowave article does not explicitly give numerical values for each component. Because the Innowave page content may have changed or may not contain all the details in a single location, it is important to keep in mind that the article might only offer general design guidelines rather than finalized component values.

Below is a consolidated summary of both the design goals typically referenced in such tutorials (from the sample answers) and a more general approach to obtaining or deriving measurements if they are not explicitly provided.

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Direct Answer to the Question
1. The Innowave article primarily presents an overall methodology for LNA design near 2.4 GHz rather than fixed, final numeric values for every individual component.
2. Typical target specifications from the article and related references include:
- Gain (S21): ~20 dB around 2.4–2.5 GHz
- Noise Figure (NF): <1 dB (desired, sometimes 1.5 dB in practical implementations)
- Input/Output Impedances: 50 Ω (with S11, S22 < -10 dB)
- Q Factor: ~10 for the input matching network (common assumption for narrowband design)

3. Some design examples (possibly from the site or from similar LNA references) list component values like:
- Inductors: e.g., L1 = 10 nH, L2 = 5.6 nH for matching networks, and an RF choke around 10–22 nH
- Capacitors: e.g., C1 = 2.2 pF, C2 = 3.3 pF, and additional pF-range capacitors for bypass or matching
- Resistors: e.g., R1 = 100 Ω (for bias or stabilization)

However, you may not find these exact values in the Innowave text if they only provided broad design steps. Some LNA tutorials show example circuits that use similar values but stress that real-life designs require iterative simulation (in ADS, Microwave Office, or an equivalent tool) and measurement-based refinement.

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Detailed Problem Analysis
Designing and characterizing an LNA typically involves:

1. ► Frequency of Operation:
The Innowave article indicates a 2.4 GHz band design. This dictates approximate matching network values and transistor bias points.

2. ► Gain (S21):
- LNAs in the 2.4 GHz band often target gains of 15–20 dB.
- Measurements use a vector network analyzer (VNA), applying a known signal at the input and measuring the output power.

3. ► Q Factor:
- The Q factor applies to resonant matching networks. In a narrowband design around 2.4 GHz, Q might be around 10 to 15, allowing selective filtering while providing decent bandwidth.
- If the article references a Q factor without presenting a final number, it may be discussing design guidelines rather than culminating in a specific measured Q.

4. ► Noise Figure (NF):
- Measurements require a calibrated noise source and a noise figure analyzer or VNA with noise figure measurement capability.
- The stated goal is often <1 dB at 2.4 GHz. Practical results can end up ~1–1.5 dB depending on transistor choice and layout parasitics.

5. ► Input/Output Impedances (S11, S22):
- Most LNAs aim for 50 Ω input and output. Return losses (|S11|, |S22|) below -10 dB are typically acceptable.
- In some references to Innowave or similar designs, improved matching might achieve S11 < -20 dB. Actual measured results often range between -10 dB and -20 dB.

6. ► Inductor, Capacitor, Resistor Values:
- The Innowave tutorial may discuss approach rather than quoting exact values. Typical values in a 2.4 GHz LNA design could be:
• Inductors of 3–10 nH for input and output matching.
• Capacitors on the order of 1–5 pF for tuning or AC coupling.
• Resistors from a few ohms up to a few hundred ohms for biasing or stability networks.
- Real values depend on transistor package parasitics, board layout, and whether you aim for optimum noise, gain, or linearity.

If the article does not provide exact measured graphs or numeric tables, you would likely see only the design procedure (biasing calculations, matching network design, stability analysis, and possibly simulated S-parameter plots). In that case, capturing “final measured” gain, noise figure, and impedances requires building the circuit, tuning the layout, and measuring in the lab.

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Current Information and Trends
Modern LNA design for 2.4 GHz typically leverages:
1. Advanced transistor technologies (e.g., GaAs pHEMT or SiGe HBT).
2. Microwave/RF design software for accurate matching network optimization.
3. EM-circuit co-simulation to account for layout parasitics.
4. Ultra-low-noise devices achieving NF < 1 dB, especially critical for sensitive receivers (e.g., Wi-Fi, Bluetooth).

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Supporting Explanations and Details
- Small-signal S-parameters are usually measured with a calibrated VNA over a frequency span (e.g., 1–4 GHz).
- The noise figure is measured with a noise-figure analyzer or by the Y-factor technique if a noise source is available.
- Q factor is not always explicitly measured in final LNA characterization; instead, engineers verify S-parameters, bandwidth, and group delay to confirm the resonant behavior matches design predictions.

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Interdisciplinary Connections
- Circuit design and electromagnetic simulation knowledge must both be applied.
- Thermal considerations can affect transistor performance at higher power levels or high ambient temperatures.

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Ethical and Legal Aspects
Not typically relevant here unless you are dealing with patented LNA topologies or proprietary manufacturer data. Always ensure compliance with local RF regulations for transmit power, but for LNAs, that is rarely an issue (they are receive-side circuits).

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Practical Guidelines
1. ► If the article does not present final measurements, perform a lab-based measurement once you replicate the design.
2. ► Double-check transistor manufacturer datasheets for typical application circuits with recommended matching values.
3. ► Use standard tools like Keysight ADS, NI AWR, or open-source tools for simulation.
4. ► Keep transmission lines and component leads short to minimize unwanted parasitics at 2.4 GHz.

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Possible Disclaimers or Additional Notes
- If you only rely on the article’s theoretical data, you may not get identical results in practice. PCB layout, component tolerances, and transistor variance can shift performance from simulations.
- Some references to a Q factor or certain inductors/capacitors might be from example LNAs that Innowave or others have published. Confirm you’re reviewing the exact same design.

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Suggestions for Further Research
- Consult transistor manufacturers (e.g., Infineon, NXP, Qorvo) for application notes.
- Look at open-source LNA projects or example designs at 2.4 GHz for known good component values.
- Investigate advanced matching networks (e.g., multi-section or harmonic termination techniques) for improved noise or linearity.

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Brief Summary
The Innowave article primarily discusses designing a 2.4 GHz LNA, aiming for ~20 dB gain, <1 dB noise figure, and 50 Ω input/output matching. Exact measured data or component values may not appear verbatim in the article—many references rely on iterative simulation and practical testing to finalize performance. Nonetheless, general guidelines suggest inductors in the low-nH range, capacitors in the 1–3 pF range, and a Q factor of around 10 in the matching networks.

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Questions for the User
1. Have you found a specific schematic or numeric table within the Innowave article that you need clarified?
2. Are you planning to replicate this design or simply comparing various LNA approaches at 2.4 GHz?

Feel free to share more details or any partial measurements you may have so we can help interpret them further!