. Below I:

1. explain the radar-range math you must use to translate TRM (transmit/receive module) power and array size into detection-range change;

2. summarize the physical/material differences between SiC and GaAs (and note GaN-on-SiC practice), with citations to credible technical sources;

3. give concrete, worked numerical examples showing how much radar detection range would change for plausible SiC vs GaAs TRM power improvements; and

4. provide a short, annotated bibliography of the best public technical references (papers, vendor app notes, industry articles) so you can read the primary material.

I avoid sensational claims — the public literature is often indirect — so I state uncertainties and show how to compute realistic range gains from stated assumptions.

A. The basic physics: how TRM power and array size affect detection range

Start with the monostatic radar equation (received power $P_r$) in simplest form:

$$P_r = frac{P_t G_t G_r lambda^2 sigma}{(4pi)^3 R^4 L}$$

For a monostatic AESA (same transmit and receive aperture) $G_t = G_r = G$, and $P_t$ is total transmitted power. Rearranged for maximum detection range $R$:

$$R propto left(frac{P_t G^2 lambda^2 sigma}{(4pi)^3 L cdot ext{SNR}_{ ext{req}}} ight)^{1/4}$$

Key takeaways (useful when comparing TRM technologies):

• Range scales as the 1/4 power of transmitted power $P_t$. Doubling $P_t$ → range × $2^{1/4} approx 1.19$ (≈19% increase).

• Range scales as the 1/2 power of antenna gain $G$. Doubling aperture gain → range × $2^{1/2} approx 1.414$ (≈41% increase).

• For AESA, total transmitted power $P_t$ is roughly N × P_mod (number of TRMs × per-module peak power). Aperture gain $G$ scales roughly with the physical aperture area (so approximately ∝ N for a fixed module footprint). Combining both effects, for AESA:

$$R propto ig( N^3 cdot P_ ext{mod} ig)^{1/4} = N^{3/4} cdot P_ ext{mod}^{1/4}$$

(That formula is a useful engineering rule-of-thumb — see Microwave Journal / TRM-spec analyses.) Microwave Journal+1

Caveat: real detection range also depends on target RCS $sigma$, operating frequency, waveform, receiver noise figure, signal processing gains, clutter, environment, and emission control tactics (LPI). The 1/4 and 1/2 scalings are valid for the radiometric core factors. Radartutorial+1

B. Why SiC TRMs matter (vs. GaAs baseline)

1. Material strengths of SiC (practical effects)

• Higher breakdown voltage & higher permissible junction temperature → enables higher RF output voltage and higher per-module peak and average power before thermal limits.

• Superior thermal conductivity → easier heat removal per module (higher duty cycle / higher average power without overheating).

• Robustness in high-power, high-temperature environments (improved reliability under heavy duty cycles). ams-publications.ee.ethz.ch+1

2. GaAs (and GaN) — where they fit

• Historically GaAs MMICs were standard for TRMs because they operate well at microwave frequencies and were manufacturable in the required yields (GaAs has been the mature mainstream). ResearchGate

• GaN (often GaN-on-SiC substrates) is now dominant in many modern AESA TRMs because GaN combines high electron mobility at microwave/RF with wide-bandgap advantages; GaN on SiC gives the thermal benefits of SiC substrate plus GaN device performance. Many Western radars have been migrating to GaN (on SiC) TRMs. Microwave Journal+1

3. Bottom line on SiC vs GaAs for TRMs

• If a TRM uses SiC power devices (or GaN on SiC), it can deliver more RF power per module and higher sustained average power than a comparable GaAs TRM because of voltage/thermal limits. That converts directly (though sublinearly) into larger detection range via the radar equation. Vendor/app notes and reviews document these power/thermal advantages. Texas Instruments+1

C. Quantifying the range impact — worked examples

Take two simple scenarios comparing a GaAs TRM array vs a SiC-enabled array. We keep aperture area / module count $N$ constant and change only per-module power $P_ ext{mod}$ as enabled by SiC.

Assumption A (conservative): SiC allows 2× per-module peak/average power vs GaAs.
Assumption B (optimistic): SiC allows 4× per-module peak/average power (through higher voltage & duty cycle).

Using $R propto P_ ext{mod}^{1/4}$ (with N constant):

• 2× per-module power → range × $2^{1/4} approx 1.189$ → ~19% increase in detection range.

• 3× per-module power → range × $3^{1/4} approx 1.316$ → ~32% increase.

• 4× per-module power → range × $4^{1/4} = 4^{0.25} approx 1.414$ → ~41% increase.

If SiC also enables more dense packaging / more modules (N increases), the gains can be larger because $R propto N^{3/4} cdot P_ ext{mod}^{1/4}$. Example:

• Increase module count by 20% ( $N o 1.2N$ ) and per-module power by 2×:

• Multiply range by $(1.2)^{3/4} imes 2^{1/4} approx 1.146 imes 1.189 approx 1.362$ → ~36% range increase.

Interpretation: realistic SiC/GaN upgrades that double per-module power and/or allow a modest increase in module count commonly translate into ~15–40% increases in detection range against a given target RCS — not a 2× or 10× leap. Big claims in press (“3× detection range”) usually conflate peak lab power with operationally sustainable average power and ignore emission control tradeoffs. See Microwave Journal and RF engineering references for the concrete Pt→range scalings. Microwave Journal+1

D. Other operational factors that can beat or erase raw-power gains

Even with SiC TRMs, the practical operational detection advantage depends on many system and tactics factors:

• LPI/EMCON tradeoffs: High radiated power increases detectability to enemy ESM; to remain stealthy, an aircraft may not use full power. So raw range advantage may be unusable in many scenarios.

• Receiver noise figure & digital processing gains: Modern signal processing (coherent integration, MTD, CFAR) can increase detection range by improving SNR; conversely, a superior receiver can compensate for some transmit shortfall.

• Aperture size and geometry: Larger physical aperture (bigger nose) may outweigh per-module power improvements. J-20 has a large nose that allows many modules — that matters. investor.northropgrumman.com

• Sustainment and yield: Manufacturing yield and long-term MTBF of SiC modules matter for real operational availability — early SiC/GaN production may face yield/quality issues that reduce practical advantage. ams-publications.ee.ethz.ch

E. Annotated bibliography — most credible public sources (read these first)

Below I list the most useful, credible and accessible technical references (reports, vendor app notes, industry articles). Each entry has a short note on why it matters.

1. “From the Radar Equation to T/R Module Specifications” — Microwave Journal (2025) — practical engineering link between radar range goals and TRM design tradeoffs; shows how Pt, G and TRM specs map to range. Useful for computing the numbers above. Microwave Journal
   Why read: concrete engineering math connecting module power to range.

2. TI application note: “Performance and benefits of GaN versus SiC” (TI / vendor app notes) — compares wide-bandgap device metrics and discusses switching, thermal, and system impacts. Texas Instruments
   Why read: vendor-level breakdown of SiC and GaN strengths/limitations.

3. Review articles on SiC/GaN devices (e.g., ResearchGate / IEEE reviews, 2023–2024) — survey on commercial SiC, GaN devices, thermal management, and switching performance. (See ResearchGate reviews and academic papers summarized earlier.) ResearchGate+1
   Why read: independent academic view on device performance and manufacturability.

4. Microwave Journal — “mmWave AESA Phased Arrays and MIMO Radar Trends” — discusses GaN on SiC MMICs and thermal advantages in military AESA practice. Microwave Journal
   Why read: industry trends showing why modern TRMs use GaN-on-SiC.

5. Radar tutorial / Radar range equation primer (Radartutorial) — fundamental equations, variables, and caveats for radar range computations. Essential reading to understand the 1/4 and 1/2 exponents. Radartutorial

6. Cooling and thermal management of TRMs — ResearchGate paper (2021) — practical thermal solutions and how cooling limits TRM performance. Important because SiC advantage is partially thermal. ResearchGate

7. Industry news & press (Northrop Grumman APG-81 / APG-77 briefings) — for real world examples of AESA fielding and constraints. Useful as operational baselines. investor.northropgrumman.com+1

F. How to read vendor/press claims critically

• Vendors often quote peak pulsed power or lab test results; operational average power (sustained) is what determines real detection range in the field.

• Range increases quoted as “X-times” seldom state whether they mean peak detection, lab conditions, or sustained operational envelope. Use the 1/4 power law to convert claimed power gains into realistic range percentages.

• Watch for aperture changes: adding modules or increasing nose size gives multiplicative gains (N^(3/4) effect) beyond per-module power increase.

G. Quick practical answers (TL;DR)

• SiC TRMs can and do improve AESA radar performance over traditional GaAs TRMs because they allow higher per-module power and better thermal duty cycles. GaN (often GaN on SiC) is the mainstream modern choice for TRMs. Microwave Journal+1

• Expected real-world detection range increases from switching GaAs → SiC/GaN TRMs are realistic in the ~15–40% range for plausible per-module power improvements and modest module-count increases — not order-of-magnitude jumps. (Exact number depends on module power improvement and aperture changes; use the 1/4 power law to convert.) Microwave Journal+1

• System-level factors (processing, LPI, ECCM, sustainment, tactics) often matter as much as raw TRM power; a mature APG-77 system’s software, networking and tactics can offset some raw hardware advantages in a newer system. Radartutorial+1