China’s top ten precision Cassegrain antenna manufacturers should be judged by measured performance, not catalog language. The key comparison is simple: VSWR ≤1.5 across the stated operating band, with cross-polarization below −30 dB. These limits matter in satellite links, tracking systems, and compact radar terminals. Low VSWR reduces reflected power at the feed. Strong polarization purity protects signal separation. In practice, results depend on frequency, reflector geometry, feed alignment, radome design, and test fixtures. Numbers need context.
A reliable manufacturer should provide swept-frequency plots, chamber conditions, calibration details, and uncertainty estimates. Ask whether the VSWR result came from a network analyzer with a calibrated waveguide transition. Check if cross-polarization was recorded on boresight and across the beam. A useful acceptance test may inspect 10-degree angular steps, temperature changes, and connector repeatability. Small assembly errors can shift the feed focus. This is where engineering experience shows.
The strongest candidates usually combine precision machining with controlled alignment procedures. Look for reflector surface accuracy, measured gain, sidelobe data, and production consistency across samples. One prototype may look excellent, yet volume units can vary. That gap deserves scrutiny. I would request raw plots, not only pass-fail tables. I would also repeat a sample test independently. Perfect figures are uncommon. Honest limitations are more credible. A sound comparison should rank evidence quality beside headline specifications.