Quantenna Communications Third Quarter Fiscal 2018 Financial Commentary October 29, 2018 Key Financial Metrics from the Quarter Key Highlights from the Quarter • Revenue of $59.3 million vs: • Record revenue from both our Wave 3 10G and Wave ▪ $50.1 million in Q3'FY17 grew 18% Y/Y 2 product segments. ▪ $53.4 million in Q2'FY18 grew 11% Q/Q • Deutsche Telekom’s award-winning Speedport Pro • GAAP gross margin of 49.7% gateway is powered by Quantenna’s Wave 3 10G • Non-GAAP gross margin of 49.8% vs: solution, using its full 12 stream capabilities for ▪ 49.0% in Q3'FY17 grew 80bps Y/Y maximum Wi-Fi performance. ▪ 48.5% in Q2'FY18 grew 130bps Q/Q • Released and sampled to customers the QSR5GU-AX • Operating margin in Q3'FY18: PLUS, the world’s only dual-band, 9-stream 802.11ax ▪ 5.0% GAAP solution. ▪ 11.8% Non-GAAP • • GAAP diluted EPS $0.10 in Q3'FY18 vs: The latest North American cable MSO initiated a full volume rollout using our Wave 3 10G technology in ▪ $0.07 in Q3'FY17 their next generation gateway bringing our total to ▪ $0.03 in Q2'FY18 four cable MSOs in deployment. • Non-GAAP diluted EPS $0.17 in Q3'FY18 vs: • ▪ $0.14 in Q3'FY17 Demonstrated over 1Gbps of Wi-Fi throughput using Quantenna's QSR10GU-AX PLUS and QSR10G, each ▪ $0.12 in Q2'FY18 • Operating cash flow of $15.8 million vs: independently communicating with commercially available mobile products from Intel Corp. ▪ $7.3 million in Q3'FY017 ▪ ($2.9) million in Q2'2018 • Orange Poland launched their new dual-band dual- • Cash, cash equivalents & marketable concurrent Wi-Fi repeater, the Smart Wi-Fi Box, based securities $132.0 million on our QV860 chipset. • DSO 30 days, down 20 days Q/Q • Integrated Plume’s Adaptive WiFi™ AI driven mesh • Annualized inventory turns 5.5x, up from solution into our QSR5GU-AX PLUS solution to deliver 5.1x Q/Q the next generation of whole-home mesh networking. Fourth Quarter FY 2018 Guidance • Announced a strategic partnership with Aerial • Revenue: $61.0 to $63.0 million technologies to bring the latest in Wi-Fi motion • GAAP gross margin: 49.9% +/- 100bps detection technology to the market. • Non-GAAP gross margin: 50.0% +/- 100bps Financial Results Call and Webcast • GAAP OPEX: $27.1 to $28.1 million Our Q3 financial results webcast and call will commence • Non-GAAP OPEX: $23.0 to $24.0 million on October 29, 2018 at 1:30 p.m. PT (4:30 p.m. ET). The • Non-GAAP Tax Exp: Approximately $300,000 webcast may be accessed at http://ir.quantenna.com/. • GAAP earnings per share: $0.08 to $0.10 An archive of the webcast will be available for 90 days • Non-GAAP earnings per share: $0.18 to $0.20 from the date of this release. Quantenna Communications, Inc. Revenue Segmentation by WiFi Technology (in percentage of revenue, unaudited) Q4 2016 Q1 2017 Q2 2017 Q3 2017 Q4 2017 Q1 2018 Q2 2018 Q3 2018 Period Ending Jan 01 '17 Apr 02 '17 Jul 02 '17 Oct 01 '17 Dec 31 '17 Apr 01 '18 Jul 01 '18 Sep 30 '18 802.11n 15% 18% 17% 15% 9% 4% 3% 2% 802.11ac Wave 2 84% 79% 79% 72% 83% 83% 71% 68% 802.11ac Wave 3 (10G) 1% 3% 4% 13% 6% 13% 26% 30% Total Semi Revenue 100% 100% 100% 100% 98% 100% 100% 100% Other 0% 0% 0% 0% 2% 0% 0% 0% Total Revenue 100% 100% 100% 100% 100% 100% 100% 100% October 29, 2018 Quantenna Q3 2018 Financial Results Page 1 of 4

Quantenna Communications, Inc. Consolidated Statements of Operations (GAAP) (in thousands, unaudited) Period Ending Q4 2016 Q1 2017 Q2 2017 Q3 2017 Q4 2017 Q1 2018 Q2 2018 Q3 2018 Jan 01 '17 Apr 02 '17 Jul 02 '17 Oct 01 '17 Dec 31 '17 Apr 01 '18 Jul 01 '18 Sep 30 '18 Revenue 37,492$ 37,891$ 47,085$ 50,108$ 41,275$ 45,117$ 53,427$ 59,349$ COGS 18,188 19,307 23,314 25,591 19,996 22,352 27,563 29,859 Gross Margin 19,304 18,584 23,771 24,517 21,279 22,765 25,864 29,490 GM % of revenue 51.5% 49.0% 50.5% 48.9% 51.6% 50.5% 48.4% 49.7% R&D 13,691 12,633 16,055 15,011 16,048 17,601 17,084 17,783 S&M 2,520 2,914 3,276 3,363 4,487 4,495 3,979 3,833 G&A 2,757 3,389 4,106 3,735 4,069 4,198 4,518 4,886 OPEX 18,968 18,936 23,437 22,109 24,604 26,294 25,581 26,502 OPEX % of revenue 50.6% 50.0% 49.8% 44.1% 59.6% 58.3% 47.9% 44.7% Operating Income (loss) 336$ (352)$ 334$ 2,408$ (3,325)$ (3,529)$ 283$ 2,988$ Op Inc % of revenue 0.9% -0.9% 0.7% 4.8% -8.1% -7.8% 0.5% 5.0% Interest & Other Income 10 3 45 120 237 334 230 243 Pretax Income (loss) 346 (349) 379 2,528 (3,088) (3,195) 513 3,231 Taxes 314 535 210 (274) (35,413) 52 (519) (648) Tax Rate 91% -153% 55% -11% 1147% -2% -101% -20% Net Income (loss) 32$ (884)$ 169$ 2,802$ 32,325$ (3,247)$ 1,032$ 3,879$ Consolidated Statements of Operations (Non-GAAP) (in thousands, unaudited) Period Ending Q4 2016 Q1 2017 Q2 2017 Q3 2017 Q4 2017 Q1 2018 Q2 2018 Q3 2018 Jan 01 '17 Apr 02 '17 Jul 02 '17 Oct 01 '17 Dec 31 '17 Apr 01 '18 Jul 01 '18 Sep 30 '18 Revenue 37,492$ 37,891$ 47,085$ 50,108$ 41,275$ 45,117$ 53,427$ 59,349$ COGS 18,170 19,264 23,272 25,553 19,954 22,318 27,501 29,809 Gross Margin 19,322 18,627 23,813 24,555 21,321 22,799 25,926 29,540 GM % of revenue 51.5% 49.2% 50.6% 49.0% 51.7% 50.5% 48.5% 49.8% R&D 13,234 11,428 14,641 13,644 14,418 15,208 14,555 15,535 S&M 2,392 2,561 2,866 2,947 3,704 3,511 3,386 3,292 G&A 2,494 2,886 3,398 2,787 3,089 3,017 3,373 3,723 OPEX 18,120 16,875 20,905 19,378 21,211 21,736 21,314 22,550 OPEX % of revenue 48.3% 44.5% 44.4% 38.7% 51.4% 48.2% 39.9% 38.0% Operating Income 1,202$ 1,752$ 2,908$ 5,177$ 110$ 1,063$ 4,612$ 6,990$ Op Inc % of revenue 3.2% 4.6% 6.2% 10.3% 0.3% 2.4% 8.6% 11.8% Interest & Other Income 10 3 45 120 237 334 230 243 Pretax Income 1,212 1,755 2,953 5,297 347 1,397 4,842 7,233 Taxes 314 535 210 (274) (108) 237 218 265 Tax Rate 26% 30% 7% -5% -31% 17% 5% 4% Net Income 898$ 1,220$ 2,743$ 5,571$ 455$ 1,160$ 4,624$ 6,968$ GAAP to Non-GAAP Reconciling Items (in thousands, unaudited) Period Ending Q4 2016 Q1 2017 Q2 2017 Q3 2017 Q4 2017 Q1 2018 Q2 2018 Q3 2018 Jan 01 '17 Apr 02 '17 Jul 02 '17 Oct 01 '17 Dec 31 '17 Apr 01 '18 Jul 01 '18 Sep 30 '18 Stock Based Compensation COGS 18$ 43$ 42$ 38$ 42$ 34$ 62$ 50$ R&D 457 1,205 1,414 1,367 1,630 2,393 2,529 2,248 S&M 128 353 410 416 584 984 593 541 G&A 263 503 708 948 980 1,181 1,145 1,163 Total 866$ 2,104$ 2,574$ 2,769$ 3,236$ 4,592$ 4,329$ 4,002$ Non-Recurring Items S&M 199$ Income Taxes (35,305)$ 185$ 737$ 913$ October 29, 2018 Quantenna Q3 2018 Financial Results Page 2 of 4

Quantenna Communications, Inc. Condensed Consolidated Balance Sheet (in thousands, unaudited) Q4 2016 Q1 2017 Q2 2017 Q3 2017 Q4 2017 Q1 2018 Q2 2018 Q3 2018 Period Ending Jan 01 '17 Apr 02 '17 Jul 02 '17 Oct 01 '17 Dec 31 '17 Apr 01 '18 Jul 01 '18 Sep 30 '18 Assets Current assets Cash, cash equivalents & marketable securities $ 117,045 $ 114,401 $ 124,389 $ 126,866 $ 118,627 $ 120,143 $ 120,082 $ 132,030 Accounts receivable 14,480 17,812 17,696 22,820 26,786 26,310 29,700 20,081 Inventory 15,820 13,361 20,985 23,700 12,662 18,420 21,391 21,578 Prepaid expenses and other current assets 2,470 3,745 4,332 2,444 2,744 2,949 2,369 6,512 Total current assets 149,815 149,319 167,402 175,830 160,819 167,822 173,542 180,201 Deferred tax assets - - - - 35,422 35,602 36,482 37,443 Property and equipment, net 4,742 6,025 6,380 11,215 12,511 12,415 12,838 13,418 Intangible and other assets, net 232 743 769 4,296 3,952 4,215 3,901 3,571 Total assets $ 154,789 $ 156,087 $ 174,551 $ 191,341 $ 212,704 $ 220,054 $ 226,763 $ 234,633 Liabilities, Convertible Preferred Stock, and Stockholders’ Equity (Deficit) Current liabilities Accounts payable $ 8,936 $ 4,658 $ 13,401 $ 13,805 $ 3,754 $ 11,833 $ 8,904 $ 10,255 Accrued liabilities and other current liabilities 10,641 15,401 19,147 27,054 21,065 22,394 23,155 23,220 Long-term debt, current portion 2,257 2,288 2,563 2,487 3,943 - - - Total current liabilities 21,834 22,347 35,111 43,346 28,762 34,227 32,059 33,475 Long-term debt 3,680 3,539 2,445 1,900 - - - - Other long term liabilities 527 - 425 3,413 3,339 3,222 3,214 2,670 Total liabilities 26,041 25,886 37,981 48,659 32,101 37,449 35,273 36,145 Stockholders’ equity (deficit) Common stock 3 3 3 3 3 3 3 3 Additional paid-in capital 290,319 292,710 298,943 302,240 308,023 313,503 321,669 324,931 Accumulated deficit and other accumulated loss (161,574) (162,512) (162,376) (159,561) (127,423) (130,901) (130,182) (126,446) Total stockholders’ equity 128,748 130,201 136,570 142,682 180,603 182,605 191,490 198,488 Total liabilities and stockholders' equity $ 154,789 $ 156,087 $ 174,551 $ 191,341 $ 212,704 $ 220,054 $ 226,763 $ 234,633 Condensed Consolidated Cash Flows (in thousands, unaudited) Q4 2016 Q1 2017 Q2 2017 Q3 2017 Q4 2017 Q1 2018 Q2 2018 Q3 2018 Period Ending Jan 01 '17 Apr 02 '17 Jul 02 '17 Oct 01 '17 Dec 31 '17 Apr 01 '18 Jul 01 '18 Sep 30 '18 Cash flows from operating activities Net income (loss) 32$ $ (884) 169$ 2,802$ 32,325$ $ (3,247) 1,032$ 3,879$ Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities Depreciation and amortization 398 479 545 542 1,103 1,125 1,138 1,204 Stock-based compensation expense 866 2,104 2,574 2,769 3,236 4,592 4,329 4,002 Deferred income taxes - - - - (35,333) (733) (908) Other 160 135 62 150 288 (50) 117 458 Changes in assets and liabilities Accounts receivable 2,826 (3,332) 116 (5,124) (3,966) 476 (3,390) 9,619 Inventory (5,552) 2,459 (7,624) (2,715) 11,038 (5,758) (2,971) (187) Prepaid expenses and other current assets (618) (1,324) (574) 1,876 (313) (205) 580 (4,143) Other assets (66) (511) (27) (252) 323 58 43 58 Accounts payable 4,100 (4,268) 10,236 2,194 (10,354) 8,185 (3,213) 1,526 Accrued liabilities (1,539) 4,707 1,890 5,020 (5,912) 1,593 150 332 Net cash provided by (used in) operating activities 607 (435) 7,367 7,262 (7,565) 6,769 (2,918) 15,840 Cash flows from investing activities Purchase of property and equipment (1,103) (1,700) (746) (4,515) (2,009) (924) (454) (2,584) Purchase of long-term investments & marketable securities - - (71,169) (32,875) (27,746) (13,801) (25,787) (8,919) Proceeds from sale and maturities of marketable securities - - 4,994 10,915 21,215 11,515 24,605 8,139 Restricted cash 1,500 - - - - - - - Net cash provided by (used in) investing activities 397 (1,700) (66,921) (26,475) (8,540) (3,210) (1,636) (3,364) Cash flows from financing activities Proceeds from issuance of common stock, net of issuance cost 406 194 3,882 477 3,122 1,438 3,874 779 Proceeds from initial public offering, net of issuance costs 97,483 - - - - - - - Principal payments on debt (551) (672) (433) (651) (650) (3,943) - - Other 881 (31) (65) - (892) (873) (360) (2,010) Net cash provided by (used in) financing activities 98,219 (509) 3,384 (174) 1,580 (3,378) 3,514 (1,231) Effect of exchange rate changes on cash & cash equivalents - - - - 113 - (152) (107) Net increase (decrease) in cash and cash equivalents 99,223 (2,644) (56,170) (19,387) (14,412) 181 (1,192) 11,138 Cash and cash equivalents Beginning of period 17,822 117,045 114,401 58,231 38,844 24,432 24,613 23,421 End of period 117,045 114,401 58,231 38,844 24,432 24,613 23,421 34,559 October 29, 2018 Quantenna Q3 2018 Financial Results Page 3 of 4

Quantenna Communications, Inc. Non-GAAP Financial Measures In addition to GAAP reporting, Quantenna provides information regarding net income, gross profit, gross margin, and operating expenses on a non-GAAP basis. This non-GAAP information excludes stock-based compensation expense and changes to deferred tax balances. These non-GAAP measures are used by the Company’s management for the purposes of evaluating the underlying operating performance of the Company, establishing internal budgets, comparing performance with internal forecasts and goals, strategic planning, benchmarking against other companies, to provide a more consistent basis of comparison and to enable more meaningful period to period comparisons. These non-GAAP measures are provided in addition to, and not as a substitute for, measures of financial performance prepared in accordance with GAAP. A reconciliation between GAAP and non-GAAP financial data is included in the supplemental financial tables included in this financial commentary. Forward-Looking Statements This press release contains forward-looking statements based on Quantenna’s current expectations, including statements regarding Quantenna’s preliminary financial results for the third quarter ended September 30, 2018, forecasted financial results for the fourth quarter of fiscal 2018, expected future business and financial performance, growth opportunities, product technologies and customer relationships. The words "believe," "estimate," "expect," "intend," "anticipate," "plan," "project," "will" and similar phrases as they relate to Quantenna are intended to identify such forward-looking statements. These forward-looking statements reflect the current views and assumptions of Quantenna and are subject to various risks and uncertainties that could cause actual results to differ materially from expectations. Among the factors that could cause actual results to differ materially from those in the forward-looking statements are the following: challenges developing new and leading edge products on a timely basis that achieve market acceptance; the complexity of the products, including integration requirements with components from other third parties that are outside of Quantenna’s control; quarterly fluctuations in revenues and operating results; intense market competition, including competition from other companies that are larger and have greater resources and broader product ecosystem offerings; ability to accurately predict future revenue and expenses; potential cancellation of customer orders; risks that Quantenna may not be able to maintain its historical growth or achieve similar levels of success with respect to new products; ability to attract and retain customers and service providers; dependence on a limited number of products and customers; intellectual property litigation risks; industry consolidation and risks associated with acquisitions, divestitures and strategic partnerships with respect to Quantenna as well as third parties; product liability risks; risks related to international operations, including the impact of increased tariffs and escalating trade tensions among countries on Quantenna and its customers, end customers, vendors and partners; dependence of Quantenna’s customers on components from other third parties; risks that Quantenna may not be able to manage strains associated with its growth; dependence on key personnel; stock price volatility; the cyclical nature of the semiconductor industry; changes in tax and other laws affecting Quantenna’s business and operations; cyberattacks; adjustments to the preliminary financial results reported in this press release and related earnings call announcement and materials for the third quarter of 2018 in connection with completion of the final closing process and procedures and preparation of our Quarterly Report on Form 10-Q; and other factors that are detailed in the Securities and Exchange (“SEC”) filings of Quantenna, which you may obtain for free at the SEC’s website at http://www.sec.gov. Quantenna disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. About Quantenna Communications Quantenna (Nasdaq:QTNA) is the global leader and innovator of high performance Wi-Fi solutions. Founded in 2006, Quantenna has demonstrated its leadership in Wi-Fi technologies with many industry firsts. Quantenna continues to innovate with the mission to perfect consumer’s Wi-Fi experience by establishing benchmarks for speed, range, efficiency and reliability. Quantenna takes a multidimensional approach, from silicon to system and software, to provide total Wi-Fi network solutions. For more information, visit www.quantenna.com. October 29, 2018 Quantenna Q3 2018 Financial Results Page 4 of 4