The ratings of five communications equipment stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

ARRIS Group, Inc. (ARRS) is on the decline this week, earning a D (“sell”) after receiving a C (“hold”) last week. ARRIS is a global communications technology company specializing in the design and engineering of broadband network solutions. To get an in-depth look at ARRS, get Portfolio Grader’s complete analysis of ARRS stock.

Applied Optoelectronics, Inc. (AAOI) earns an F (“strong sell”) this week, moving down from last week’s grade of C (“sell”). The stock gets F’s in Earnings Surprise and Cash Flow. As of April 16, 2015, 11.8% of outstanding Applied Optoelectronics, Inc. shares were held short. The stock has a trailing PE Ratio of 46.50. For more information, get Portfolio Grader’s complete analysis of AAOI stock.

This week, Dragonwave Inc.’s (DRWI) rating worsens to a D from the company’s C rating a week ago. DragonWave is a producer of high-capacity packet microwave solutions which support networking and other data transmission needs. The stock gets F’s in Equity and Cash Flow. Shares of the stock have been changing hands at an unusually rapid pace, four times the rate of the week prior. To get an in-depth look at DRWI, get Portfolio Grader’s complete analysis of DRWI stock.

Clearfield, Inc.’s (CLFD) rating weakens this week, dropping to an F versus last week’s D. Clearfield offers telecommunications equipment and products in the United States. The stock gets F’s in Earnings Growth, Earnings Momentum and Sales Growth. Trade volume is up 407.3% from the previous week. The stock’s trailing PE Ratio is 46.80. For more information, get Portfolio Grader’s complete analysis of CLFD stock.

Slipping from a C to a D rating, Sonus Networks, Inc. (SONS) takes a hit this week. Sonus Networks provides voice infrastructure solutions for wireline and wireless service providers. To get an in-depth look at SONS, get Portfolio Grader’s complete analysis of SONS stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.